This study examined HIV testing behaviours, perceived vulnerability to HIV and correlates of sexual risk behaviours of young adult Latino and African American male gang members in Los Angeles, California. Data were collected from 249 gang members aged 18-26 years. The majority (59%) of gang members reported unprotected vaginal intercourse (UVI) in the past 12 months. Only one-third (33.2%) of gang members had ever been tested for HIV. In our multivariate analysis, gang members who reported UVI were more likely to have engaged in the following behaviours: had sex with someone they just met (adjusted odds ratio [AOR] = 4.51), had sex with someone they think or know had a sexually transmitted infection (STI; AOR = 4.67) or had sex while incarcerated (AOR = 8.92). In addition, gang members with a higher perceived vulnerability to HIV were less likely to report UVI in the previous 12 months (AOR = 0.75). These findings offer implications for development of an HIV prevention intervention for young Latino and African American male gang members.