Purpose: This study investigated the health and socioeconomic status of single-parent and partnered families, and examined the intersection between sex and single-parent status focusing on inequalities of health and socioeconomic status. Methods: This was a cross-sectional study using the data from the nationally representative 2005 Korean National Health and Nutrition Examination Survey. A total of 14,827 respondents had custody of their own children and other family members (13,943 were coupled families and 891 were single-parent). Results: Our result indicate that single-parent had poorer health status and were more likely to have lower educational attainment, lower household income, no home ownership and be unemployed. However, the association between single-parent status and socioeconomic and health inequality were in divergent ways according to sex. The most socioeconomically disadvantaged were single-parent women. Inequalities in health differ markedly by sex but vary little according to single-parent status. Conclusions: An uneven distribution of socioeconomic resources might help us to understand why single-parent, both women and men, have worse health than parents who live together. Previously recognized sex gap with regard to health status also might help us to understand the difference in health between single-parent men and single-parent women found here.