From 2019 to 2020, Alive & Thrive (A&T) focused on engaging and strengthening the capacity of 10 private health facilities in Lagos State to provide high-quality breastfeeding and infant and young child feeding (IYCF) support services. In partnership with the local government accreditation agency and the Equitable Health Access Initiative, A&T trained participating health facilities on the Baby-Friendly Hospital Initiative (BFHI), which aims to provide health workers with the skills and confidence to support mothers with breastfeeding (WHO, 2018). A&T also promoted breastfeeding among mothers, fathers, and influential family members though a range of social and behaviour change interventions. This brief describes A&T’s approach to strengthen the capacity of private healthcare providers with supporting breastfeeding, summarizes the results of the evaluation conducted by RTI International, and offers key learnings for future programs and interventions.