OBJECTIVE: To explore female and transvestite sex workers' perceptions of risk in the sex work environment in Serbia. DESIGN: Qualitative interview study. SETTING: Street based locations for sex work in Belgrade and Pancevo, Serbia. PARTICIPANTS: 31 female and transvestite sex workers. RESULTS: Violence, including police violence, was reported as a primary concern in relation to risk. Violence was linked to unprotected sex and the reduced capacity for avoiding sexual risk. Participants reported that coerced sex was routinely provided to the police in exchange for freedom from detainment, arrest, or fine, and was enforced by the perceived threat of violence, sometimes realised. Accounts contained multiple instances of physical and sexual assault, presented as abuses of police authority, and described policing as a form of moral punishment. This was largely through non-physical means but was also enforced through physical violence, especially towards transvestite and Roma sex workers, whose experience of police violence was reported as relentless and brutal and connected with broader social forces of discrimination in this setting, especially towards Roma. CONCLUSION: Preventing violence towards sex workers, which can link with vulnerability to sexually transmitted infections, is a priority in Serbia. This requires monitoring perpetrators of violence, providing legal support to sex workers, and creating safer environments for sex work.