Measurement of the effectiveness of violence prevention interventions is in a developmental phase. Social capital provides a framework within which to examine this topic from a community perspective. The purpose of this study was to examine the relationships among three measures of social capital and attitudes about violence among Mexican-Americans. A cross-sectional survey was conducted of households randomly selected by block in two adjacent Mexican-American communities. Demographics, attitudes about and experiences with violence, and three measures of social capital (collective efficacy, neighborhood block conditions, community integration) were assessed. Descriptive, bivariate, and logistic regression analyses were used to examine indicators of violence attitudes and experiences. Of the 473 respondents who completed the survey, 323 (68%) were female, 393 (83%) were Mexican-American, 395 (84%) were born in the US, and 346 (72%) owned their own homes. Participants with high measures of collective efficacy were 1.68 times more likely to have negative attitudes about violence (CI 1.06-2.65) and 15.25 times more likely to have negative attitudes about couple violence (CI 9.05-25.74). Participants with high scores on neighborhood block conditions were 2.33 times more likely to have negative attitudes about couple violence (CI 1.40-3.87). Scores on community integration were not significant indicators of participants' tolerance and experiences with violence. Two measures of social capital were positively associated with and predictive of negative attitudes toward violence. The results suggest that primary violence prevention programs in Mexican-American communities should focus on strengthening a sense of collective efficacy and improving neighborhood conditions.