Introduction: There are no studies on how much primary care research from Japan has spread internationally. In this study, we aimed to investigate Japan's contribution to high-impact international primary care journals.

Methods: We used the PubMed database and reviewed abstracts to examine the frequency of articles reporting clinical research or systematic reviews originating from Japan that were published in 5 high-impact international primary care journals from January 2011 to June 2016. We calculated the proportion of articles from Japan in the selected journals by year and journal.

Results: Of the total articles (2,602), the proportion of Japanese articles in 5 high-impact international primary care journals was 0.15% (4 articles).

Conclusion: Currently, Japan's contribution to high-impact international primary care journals is very small. In Japan, the development of research infrastructure, the education of researchers, and networks for research collaboration may be needed for international dissemination of primary care research.