Objective To examine how different dimensions of social capital and health behaviour are associated.

Design Cross-sectional data of the Health 2000 Health Examination Survey including a personal interview and self-administered questionnaires.

Setting Representative sample (N=8028) of the Finnish adult population.

Participants 6986 (87%) adults aged 30 years or over.

Main Outcome Measures Non-smoking, non-excessive drinking, leisure-time physical activity, daily use of vegetables, adequate duration of sleep.

Results Social capital was found to be associated with health behaviour. The dimension of social participation and networks was positively associated with every type of health behaviour. High levels of trust and reciprocity were related to non-smoking and adequate duration of sleep, and high levels of social support to adequate duration of sleep and daily use of vegetables. These associations persisted after controlling for age, gender, education and living arrangements. According to our findings, structural social capital seems to be associated with health behaviour more strongly than cognitive social capital.

Conclusion Irrespective of their social status, people with higher levels of social capital—especially in social participation and networks—engage in healthier behaviour. When trying to reduce health inequalities, one strategy could be to promote social participation especially among people in danger of social exclusion.