BackgroundQuality of life (QoL) is a multidimensional concept that is affected by various factors. According to the literature, social capital is one of the key determinants of QoL that improves the living conditions of the entire community. This study aimed to investigate the association between social capital and QoL in pregnant women.MethodsThis cross-sectional study included 240 pregnant women with a mean age of 27.98 years who were referred to healthcare centers in Qazvin, Iran. A two-stage random sampling method was used to select the health centers and participants. Social capital, QoL, demographic and obstetric characteristics were assessed.ResultsThe mean scores of social capital, physical and mental dimensions of quality of life were 67.43, 70.2 and 71.88 respectively. All dimensions of social capital except for family and friends’ connection and tolerance of diversity had positive significant correlations with the physical and mental health dimensions of quality of life (r = 0.17 to 0.28 p < 0.05). A univariate regression model revealed that social capital had a significant association with both the physical health (B = 0.40, 95% CI: 0.19–0.61, p < 0.001) and mental health (B = 0 .44, 95% CI: 0.18–0.58, p < 0.001) dimensions of pregnant women’s quality of life. In the adjusted model, each unit increase of social capital increased pregnant women’s QoL in both the physical health and mental health dimensions.ConclusionSocial capital has a significant association with women’s QoL during pregnancy. Therefore, QoL during pregnancy could be improved by considering physical, psychological and social components of their healthcare.