The Bold Idea for Girls (BIG) project has shown that providing an integrated program of HIV evidence-based behavioural interventions, gender and life-skills, and vocational and entrepreneurial skills to girls aged 15–24 years in urban informal settlements could increase knowledge and practice of HIV/STI prevention and raise their social-economic status. This project will enable HOPE Worldwide Kenya (HOPE) to expand BIG to 500 new beneficiaries in Mukuru, comparing their sexual and reproductive health knowledge and behaviours with a control group of girls that will be matched for age, education and village, while also supporting follow-ups with the original cohort, as well as training, market research and business model development, training, monitoring and evaluation.