In the South African urban areas of Atlantis and Khayelitsha, men and boys see gang membership and violence (including gang-related violence) as part of 'being a man'. In this context, life itself is perilous and vulnerable. This article draws on the narratives of boys about their lives, and explores some key questions relating to gender, development and HIV. These include: how are men's and boys' ideas about sexuality created, and what does this suggest about the kinds of HIV interventions that should be offered? In particular, how does the reality of everyday life in urban South Africa affect male perceptions of risk in relation to HIV/AIDS? And how can men and boys best be targeted in HIV prevention and treatment work?