Surgical site infections (SSI) are major complications after surgical procedures, since they prolong the hospital stay, increase treatment costs and diminish patient satisfaction markedly. In the United States SSI surveillance is carried out in the framework of the NNIS system; at present more than 300 medical institutions are participating. In comparison with Europe and the United States SSI surveillance had a late start in Japan. The Japanese Society of Environmental Infections established the Japanese Nosocomial Infection Surveillance System in 1998 and initiated SSI surveillance in the same year. Up to October 2003, in total 20,948 cases from 36 institutions have been registered. SSIs occurred in 1,394 cases, this corresponds to an incidence of 6.7%. When we look at the numbers of SSIs by the organs operated on, the incidence figures in the field of gastrointestinal surgery were by far the highest ones. Since July 2002, 50 institutions all over Japan are participating in SSI surveillance that has developed into a national scheme under the auspices of the Japanese Ministry of Health and Welfare. The activities supervised by the Ministry will for some time be limited to these 50 institutions. Aiming at a further spread and quality enhancement of SSI surveillance in Japan in October 2002 the SSI Surveillance Study Meeting was founded. It is anticipated that through the activities of this organisation a large number of institutions will participate in SSI surveillance, that reliable surveillance data will established and that SSIs will decrease in Japan.