The objective of this study was to assess environmental secondhand smoke exposure and tobacco control policy at 5 venues. A cross-sectional study was conducted involving 134 settings and 2727 adults in Zhejiang, China. The results show that the proportions of venues that had complete smoking ban were as follows: health administrative organizations (71.9%), hospitals (70.0%), schools (66.7%), public transportation vehicles (24.0%), and government agencies (11.8%). The proportions of venues where smoking was noticed were as follows: public transportation vehicles (88.0%), government agencies (47.1%), hospitals (46.7%), health administrative organizations (40.6%), and schools (30.0%). Venues with completely indoor smoking ban were 5 times more likely to be smoke-free at the time of survey than other venues without smoking ban (odds ratio = 5.39, 95% confidence interval = 1.92-15.14). It indicated that implementation of indoor smoking ban can reduce indoor secondhand smoke exposure.