Background The slow progress of tobacco control policy in Japan reflects the tension among the interests of the Finance Ministry (which remains the majority shareholder of Japan Tobacco, Inc), the Health Ministry, tobacco growers and consumers.

Methods We sought to examine regional disparities in compliance with national tobacco control legislation (the 2003 Health Promotion Law). Specifically, we sought to examine whether prefecture-level compliance with legislation was correlated with decreases in smoking prevalence, and decreases in lung cancer mortality rates. We also examined whether prefectural involvement in growing tobacco was associated with lower compliance with the law.

Results From 2001 to 2007, higher prefectural compliance with tobacco control laws was associated with decreased prevalence of smoking. Decreased tobacco consumption was in turn associated with declining lung cancer mortality. Prefectures involved in growing tobacco exhibited lower levels of compliance with national tobacco control laws. The same prefectures also exhibited the worst improvement in smoking prevalence.

Conclusions This study in Japan suggests that tobacco control policies are being unevenly implemented across prefectures, and that measures to counteract the influence of local tobacco culture are required to reduce the disparities in regional tobacco control outcomes in that country.