What is Vancouver referencing style?

Vancouver is a numbered (author-number) referencing system used mainly in medicine and the health sciences. Sources are numbered in the order they are first cited in the text, and the reference list at the end is arranged in that numerical order rather than alphabetically. It takes its name from a 1978 meeting of medical journal editors in Vancouver, Canada, the group that became the ICMJE.

How do you cite in text in Vancouver style?

Insert a number where you use the source: in parentheses (1), square brackets [1], or as a superscript. Use the same number every time you cite that source. For several sources use commas (1,3,7) and a hyphen for a run of consecutive numbers (2-5). Your journal or department decides which bracket form to use, so stay consistent.

How do you reference a journal article in Vancouver style?

Author surname and initials (up to six, then et al.). Title of article. Abbreviated journal title. Year Month Day;Volume(Issue):Pages. Example: Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

How do you reference a website in Vancouver style?

Author or organization. Title [Internet]. Place of publication: Publisher; date of publication [updated date; cited date]. Available from: URL. Every internet example on NLM's samples page carries a [cited YYYY Mon DD] date, so include the date you consulted the site.

Is Vancouver the same as NLM style?

Very similar. Vancouver follows recommendations from the International Committee of Medical Journal Editors (ICMJE), which are based on NLM (National Library of Medicine) standards. For practical purposes, they're often interchangeable, but some journals have specific preferences.

Do I abbreviate journal titles?

Yes, use NLM/MEDLINE abbreviations. You can look these up in the NLM Catalog. Common examples: N Engl J Med, BMJ, Lancet.

How do I punctuate reference numbers in text?

The ICMJE Recommendations say to identify references by Arabic numerals in parentheses. They do not say where the number sits relative to punctuation, and journals that use superscripts or brackets set their own rule. For multiple citations, a common form is commas without spaces (1,2,5) and a hyphen for ranges (1-5). Follow the target journal's instructions for authors.

Vancouver Referencing (ICMJE/NLM): Format and Examples

Vancouver style at a glance

In the text: a number for each source, assigned in the order sources first appear.

Solid-organ transplantation in HIV-infected patients has been discussed in the medical literature (1).

In the reference list: entries in the same numerical order.

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

Source	Vancouver reference format
Journal article	Author AA, Author BB. Title of article. Abbreviated Journal Title. Year Mon Day;Volume(Issue):Pages.
Book	Author AA. Title of book. Edition. Place of publication: Publisher; Year.
Book chapter	Author AA. Title of chapter. In: Editor AA, editor. Title of book. Place: Publisher; Year. p. Pages.
Website	Author or Organization. Title [Internet]. Place: Publisher; Date [cited Year Mon Day]. Available from: URL

How to build a reference in five steps:

Write authors as surname plus initials with no periods or commas between them: Halpern SD.
List up to six authors; if there are more, list six and add "et al." (NLM's sample page notes that NLM itself now lists all authors, so check what your journal wants.)
Give the article title in sentence case with no quotation marks or italics.
Abbreviate the journal title the way the NLM Catalog does, followed by a period.
Add the date, volume, issue and pages with no spaces: 2002 Jul 25;347(4):284-7.

The Official Source

Vancouver style is governed by the International Committee of Medical Journal Editors (ICMJE) through their Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals at icmje.org.

For detailed formatting, the ICMJE points to Citing Medicine, 2nd Edition published by the U.S. National Library of Medicine (NLM), freely available at ncbi.nlm.nih.gov/books/NBK7256.

Quick Overview

Vancouver uses a numbered citation system:

In-text citations — numbers in parentheses, brackets, or superscript
Reference list — numbered entries in order of first citation

The ICMJE's own account is that a small group of editors of general medical journals met informally in Vancouver, British Columbia, in 1978 to establish guidelines for the format of manuscripts. The group became known as the Vancouver Group and later evolved into the ICMJE. Its reference formats were developed by the National Library of Medicine.

In-Text Citations

Citations are numbered consecutively in the order they first appear. You can use parentheses (1), square brackets [1], or superscript¹—be consistent throughout your paper.

Basic Citation

Solid-organ transplantation in HIV-infected patients has been discussed in the medical literature (1).
Solid-organ transplantation in HIV-infected patients has been discussed in the medical literature.¹

Multiple Sources

Separate with commas; use a hyphen for three or more consecutive numbers.

Several studies support this conclusion (1,3,7).
This finding has been replicated extensively (2-5).

Citing the Same Source Again

Reuse the original number each time you cite that source.

As noted above (1), the question has been debated.

Author Named in Text

You can mention authors, but still include the citation number.

Halpern et al (1) discussed solid-organ transplantation in HIV-infected patients.

Reference List Basics

The reference list is numbered consecutively in citation order (not alphabetical). Each entry starts with the reference number.

Basic Structure

#. Author(s). Title of article. Journal Abbreviation. Year Mon;Volume(Issue):Pages.

Journal Article

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

Journal Article (More Than 6 Authors)

List the first six authors followed by "et al."

Rose ME, Huerbin MB, Melick J, Marion DW, Palmer AM, Schiding JK, et al. Regulation of interstitial excitatory amino acid concentrations after cortical contusion injury. Brain Res. 2002;935(1-2):40-6.

Six is the Vancouver cut-off for the reference list, and every style sets its own: APA 7 lists up to 20, MLA 9 up to two, Chicago 18 and IEEE up to six like Vancouver, and Harvard (Cite Them Right) all of them unless your institution's guide says otherwise. Citing multiple authors puts the thresholds side by side, in text and in the reference list.

Journal Article with DOI

Zhang M, Holman CD, Price SD, Sanfilippo FM, Preen DB, Bulsara MK. Comorbidity and repeat admission to hospital for adverse drug reactions in older adults: retrospective cohort study. BMJ. 2009 Jan 7;338:a2752. doi: 10.1136/bmj.a2752.

Citing a journal article shows where each element comes from, and citing preprints covers medRxiv, bioRxiv and the other platforms a health-science reference list often has to account for.

Book

Murray PR, Rosenthal KS, Kobayashi GS, Pfaller MA. Medical microbiology. 4th ed. St. Louis: Mosby; 2002.

Chapter in Book

Meltzer PS, Kallioniemi A, Trent JM. Chromosome alterations in human solid tumors. In: Vogelstein B, Kinzler KW, editors. The genetic basis of human cancer. New York: McGraw-Hill; 2002. p. 93-113.

Website

This is NLM's own sample reference for a homepage. The copyright date (c2016) and the date you consulted the site (cited 2016 Dec 27) are part of the format, so replace them with the dates that apply to your own use of the site.

eatright.org [Internet]. Chicago: Academy of Nutrition and Dietetics; c2016 [cited 2016 Dec 27]. Available from: https://www.eatright.org/.

Organization as Author

NLM's sample for a book with an organization as author:

American Occupational Therapy Association, Ad Hoc Committee on Occupational Therapy Manpower. Occupational therapy manpower: a plan for progress. Rockville (MD): The Association; 1985 Apr. 84 p.

And for a journal article with an organization as author:

Diabetes Prevention Program Research Group. Hypertension, insulin, and proinsulin in participants with impaired glucose tolerance. Hypertension. 2002;40(5):679-86.

Key Vancouver Conventions

Author names — surname first, then initials without periods: Halpern SD (not Halpern, S.D.)
Journal abbreviations — use NLM/MEDLINE standard abbreviations (e.g., N Engl J Med, BMJ, Lancet)
No italics — journal names and book titles are not italicized in Vancouver style
Dates — format as Year Mon Day: 2002 Jul 25
Page numbers — elide ending numbers: 284-7 (not 284-287)
Et al. — use after six authors when there are more than six
Punctuation in journal abbreviations — no periods inside the abbreviation (N Engl J Med, not N. Engl. J. Med.); a single period follows the whole title

Common Mistakes to Avoid

Alphabetizing references — Vancouver references are numbered by citation order, not alphabetically.
Italicizing journal names — Vancouver does not use italics for journal or book titles.
Full page numbers — elide page ranges: use 284-7 not 284-287.
Periods in initials — no periods: Smith AB (not Smith A.B.)
Wrong journal abbreviations — use NLM standard abbreviations. Search the NLM Catalog to verify.
Inconsistent citation format — choose parentheses, brackets, or superscript and use it consistently throughout.

Who Uses Vancouver Style?

Vancouver is used by medical and health-science journals that follow the ICMJE Recommendations, and by university departments that teach it for coursework and theses. Two neighbouring numbered styles cover much of the same literature: AMA, the standard across the JAMA Network and much of the health sciences, and NLM, the reference format behind PubMed and Citing Medicine itself. Much of what a health-science review cites is not a journal article at all — clinical practice guidelines have their own pattern in each of these styles.

The ICMJE website lists journals that state they follow its Recommendations. Individual journals still differ on details such as superscripts versus brackets, so check the instructions for authors.

Further Resources

ICMJE Recommendations: official manuscript guidelines, including the references section
Citing Medicine, 2nd edition: NLM's full style guide, free online
NLM Samples of Formatted References for Authors of Journal Articles: the source of the reference examples on this page
NLM Catalog: look up journal title abbreviations
ICMJE Uniform Requirements, October 2008 (archived): the source of the history of the Vancouver Group given above

Accessed 22 September 2026.

Wonders formats bibliographies in Vancouver style, among six citation styles, and exports references as BibTeX, RIS or CSV or saves them to Zotero. Check each generated reference against your journal's instructions for authors. If you are a nursing or health student, we wrote up what it does and does not do for a nursing literature review.