In this population-based cross-sectional study of women of reproductive age in Tehran, Iran, the social capital integrated questionnaire and socio-demographic questionnaire were used. The highest mean scores were related to social cohesion and inclusion dimension (55.72 ± 11.94) and the lowest mean scores to groups and networks dimension (31.78 ± 19.43). Stepwise multiple linear regressions showed the significant association between dimensions of social capital and certain socio-demographic variables, particularly family income. Policy makers should help low-income families by designing effective interventions for improving the status of social capital in this group, because it is considered one of the social determinants of health.