The associations between marital status and poor mental health are investigated, and whether social capital, trust, and economic stress attenuate the associations between marital status and poor mental health. The public health survey in Skåne (southern Sweden) 2008 is a cross-sectional study including 28,198 persons aged 18-80.Logistic regression models investigate associations between marital status and mental health, adjusting for age, country of birth, education, emotional support, instrumental support, trust in others, and economic stress. A 13.8% prevalence of the men and 18.2% of the women had poor mental health. Significantly higher odds ratios of poor mental health for the unmarried, divorced and widows/widowers compared to married/cohabitating remained throughout the analyses. Trust and economic stress only moderately attenuated these associations.