Objective To determine the coverage of smoking restriction policies in indoor workplaces in China and to assess the relationships between these restrictive policies and secondhand smoke (SHS) exposure and smoking behaviours.

Methods A cross-sectional household survey was conducted in six counties in Sichuan, Jiangxi and Henan provinces in 2004. Using a standardised questionnaire, information on demographic characteristics, knowledge, attitudes and behaviours related to smoking and SHS exposure was collected through face-to-face interviews by trained local investigators among 12 036 respondents. Of respondents, 2698 individuals worked mainly indoors and were included in data analysis.

Results Only 28.5% of respondents reported that indoor workplaces had a smoke-free policy. Even when respondents reported smoke-free policies, 41.1% smokers reported that they were non-compliant with policies and smoked at work. In addition, 32.0% of non-smokers reported being exposed to SHS at work despite smoke-free policies. Non-smokers who reported no smoking restriction policies were 3.7 times more likely to be exposed to SHS than those working in smoke-free workplaces (adjusted OR 3.7, 95% CI 1.3 to 10.1). On average, respondents complying with smoke-free policies smoked 3.8 fewer cigarettes than those reporting no policies in their workplaces at a marginally non-significant level (p=0.06) (adjusted mean difference −3.8, 95% CI −8.0 to 0.5).

Conclusions In China, few workplaces have implemented policies to restrict smoking, and, even in workplaces that have policies, workers report exposure to SHS while at their places of employment. Many workers report a lack of compliance with smoke-free policies. China needs better implementation of SHS policies to promote compliance. Working to improve implementation of smoke-free policies would promote cessation since Chinese smokers who were compliant with these efforts reported smoking fewer cigarettes per day.