House and Ball communities (HBCs), represent a prime context for human immunodeficiency virus prevention with African American young men who have sex with men and transgender persons. This study sought to understand the composition and function of social support and sexual networks of HBC members in Los Angeles, California (N = 263). Participants were recruited using venue-based sampling and asked to report on sexual health advice seeking, alcohol use and illicit substance use. Participants were more likely to seek sexual health advice from social support network members compared with sexual network members [odds ratio (OR): 2.50, P < 0.001]. HBC members were more likely to get drunk (OR: 1.57; P < 0.05) and use illicit substances (OR: 1.87; P < 0.10) with House members and sexual network members compared with non-House members and social support network members. Health promotion programs tailored for the HBC should encourage open communication regarding sexual health; these interventions must include information about the role of substance use in sexual risk taking.