The impact of a publication in a particular medical area is reflected by the number of times the article is included as a citation. It is not known, however, which articles are cited the most in primary care journals. In our study, we aimed to identify the 100 most cited articles in primary care medicine and analyze their characteristics.We searched the Science Citation Index Expanded for articles published in 18 primary care journals using the subject category "Primary health care." We identified 100 articles in primary health care that were the most cited. We analyzed the characteristics of these articles using the title, number of citations, citation density, year of publication, journal source, decade published, country of origin, institution, author names, and type of article.The 100 articles that were cited the most were published between the years 1977 and 2009. The 1990s decade was the most productive decade. The number of citations ranged from 117 to 775. The articles were published in 9 journals and the journal with the largest number of most cited articles (n = 33) was the Journal of Family Practice. This was followed by the British Journal of General Practice (n = 17) and the journal Family Practice (n = 16). The United States was the most productive country (n = 59); the United Kingdom was next (n = 25) and this was followed by Canada (n = 5) and The Netherlands (n = 5). The most popular article type was a review article and this was followed by a qualitative study and then methodological study.Our study provides insight into the historical development of primary care studies, based on citations, and provides the foundation for further investigations.