This study documents gay men's communication patterns about unprotected sex. Gay men (n = 206) completed a structured interview about their social networks. The 167 men who had had unprotected sex identified 1390 social relations; 32.6% had involved discussing an episode of unprotected sex. Discussions about unprotected sex were associated with the nature of the relationship, whether the other party was gay or lesbian, how often the parties spent time together, whether the relationship had been sexual, and the density of the other parties' social network. Social networks provide an important context for the maintenance of safe sex cultures.