Objective: We examined whether individual-level social capital--the intangible resources in a community available through membership in social networks or other social structures and perceived trust in the community--was associated with acculturation, depression and anxiety symptoms, and perceived access to services among women of Mexican ancestry. Method: Recruited through venue-based targeted sampling in King County, Washington, 205 women of Mexican descent ages 18 to 64 years who differed in socioeconomic status and nativity completed a cross-sectional survey. Half completed the survey in Spanish and half in English. Structural equation modeling was used for model testing. Results: Social capital increased with level of acculturation and was negatively related to depression and anxiety; it had no direct association with perceived access to services. Social capital mediated the relation between acculturation and both depression and anxiety symptoms. Acculturation had no direct association with psychological distress but was directly associated with perceived access to services. This community sample of women reported high levels of psychological distress, with 20% to 26% of women meeting diagnostic criteria for depression or anxiety. Conclusions: Social capital can be assessed at the individual level, increases with acculturation, and may be a potential target for interventions to improve mental health among Mexican American women residing in the United States. (Contains 3 tables and 1 figure.)