Between 1997 and 2003, four studies on hawkers and apprentices in motor parks and work shops in south west, Nigeria were carried out to evaluate the effectiveness of interventions aimed at preventing HIV infection and gender based violence (GBV). The studies were in 3 phases namely baseline survey, intervention and end line survey. Interventions consisting of:--development and distribution of education materials and training programmes for the police, judiciary, instructors, drivers, traders and apprentices/hawkers, including micro-credit facilities were implemented in some of the studies. The major lessons learnt were that: Young girls working in the informal sector of the Nigerian economy face dual risks of HIV infection and GBV and yet they are seldom targets of intervention; Many had been victims of GBV and did not seek redress either because they accept it is their lot, are afraid of being stigmatized or are put off the prolonged legal system; Perpetrators tend to deny their involvement in violence; Despite the challenges involved, interventions implemented among female apprentices and hawkers, especially those that involve multiple stakeholders, made a difference in protecting this group from dual risks of GBV and HIV/AIDS infection. We recommend more intervention programmes for this population, and regulation of activities in the informal sector of the Nigerian economy.