BACKGROUND: Gender inequity is manifested in the social and economic burden women carry in relation to men. We investigate women's experiences of gender relations from childhood to adult life and how these may have led to and kept women in sex work. METHODS: Participants were drawn from an ongoing epidemiological cohort study of women working in high HIV/STI risk environments in Kampala. From over 1000 enrolled women, we selected 101 for a qualitative sub-study. This analysis focuses on 58 women who engaged in sex work either as a main job or as a side job. In-depth life history interviews were conducted to capture points of vulnerability that enhance gender inequity throughout their lives. RESULTS: Most participants were young, single parents, poorly educated, who occupied low skilled and poorly paying jobs. All women knew their HIV status and they disclosed this in the interview; 31 were uninfected while 27 said they were infected. Parental neglect in childhood was reported by many. Participants described experiences of violence while growing up sometimes perpetuated by relatives and teachers. Early unwanted pregnancies were common and for many led to leaving school. Some women stated a preference for multiple and short-term money-driven sexual relationships. Needing to earn money for child care was often the main reason for starting and persisting with sex work. Violence perpetrated by clients and the police was commonly reported. Alcohol and drug use was described as a necessary "evil" for courage and warmth, but sometimes this affected clear decision making. Many felt powerless to bargain for and maintain condom use. Leaving sex work was considered but rarely implemented. CONCLUSIONS: Inequities in gender and power relations reduce economic and social opportunities for better lives among women and increase risky sexual behaviour. Interventions focused on these inequities that also target men are crucial in improving safer practices and reducing risk.