Efforts to reduce HIV among gay, bisexual and other men who have sex with men include increasing awareness and uptake of pre-exposure prophylaxis (PrEP). Social capital may facilitate engagement in HIV prevention. Membership of social groups including chosen families (i.e. friends as family relationships) - one potential indicator of social capital - may be protective against HIV risk and infection. In this cross-sectional quantitative study, we examined social capital items and social group membership in association with PrEP outcomes. In 2014, the New Orleans arm of the National HIV Behavioral Surveillance recruited 353 HIV-negative men, of whom 46% identified as Black, Latino or Other Race and 54% as Non-Hispanic White, using venue-based sampling to complete a structured survey. Multivariable logistic regression models tested the relations between social group membership and social capital with PrEP indicators. Men who reported community group participation were more likely to be aware of PrEP compared to those who did not. Men in chosen families associated with a family name were least likely to be aware of and willing to take PrEP compared to those not in any other social groups. Social group membership is a potential social capital indicator for assessing HIV prevention among men.