Aims To provide accurate and timely data on the determinants of smoking in countries of the former Soviet Union in order to facilitate the development of effective tobacco control policies in the region. Such data are urgently needed given the absence of accurate comparative data in the region and the recent changes experienced. Design Cross-sectional surveys using standardized methods and representative samples of the adult population in eight former Soviet Union countries conducted as part of the EU-Copernicus Project Living Conditions, Lifestyle, and Health study. Setting Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia and Ukraine. Participants A total of 18 428 adults aged 18 plus; response rates 71-88%. Measurements The association of smoking with demographic and socioeconomic factors was investigated using multiple logistic regression analyses, stratifying by gender. Findings Age was a strong determinant of smoking in both genders, with elderly individuals being less likely to smoke. Men who were more socially disadvantaged (less educated, poorer economic situation and/or less social support) were more likely to smoke. In women, living in larger urban areas was the strongest predictor of smoking. Divorced, separated or widowed women were also more likely to smoke than married women. Muslim respondents smoked less frequently compared with other respondents. Conclusions Smoking is a major public health issue in the FSU particularly affecting socially vulnerable men and young women living in urbanized areas. These high-risk groups should be targeted in future smoking prevention and cessation strategies in the region.