The purpose of this study was to identify trends in the medical articles published in Japan. The data were mostly collected from the Igaku Chuo Zasshi. Almost 1.7million medical articles were published between 1995 and 1999 in Japan, and they were analyzed and classified according to “article type.” The results of this study showed that the rate and number of conference abstracts in Japanese medical journals had been increasing, and the MEDLINE data revealed annual increases in the number of Japanese authors' articles contributed to foreign medical journals. English is the international language, and articles in English in scientific fields tend to be evaluated more favorably than domestic language articles. Thus some authors tend to write articles in English and not to write in their native language. The role of Japanese language journals will change. The trend to contribute original articles to domestic journals will decrease in all non-English speaking countries.