Improving women’s sexual and reproductive health (SRH) requires innovative strategies to maximise potential synergies between components of care. Most adverse reproductive health outcomes stem from unintended pregnancy, and acquisition and transmission of reproductive tract infections. Although proven solutions exist, their implementation has been fragmented, with limited population impact, and little access for populations most at risk, such as sex workers. Integration of SRH services is key to achieving universal access to reproductive health. However, with weakened health systems and an HIV pandemic, the way forward is uncertain. The essential package of services and models for delivering them at high coverage in resource-limited settings are unclear. To address this, we propose a ‘diagonal’ strategy, incorporating both ‘horizontal’ health systems strengthening and more targeted ‘vertical’ approaches. Horizontal programmes can reach large numbers of women, while vertical programs target high-risk populations, difficult to reach through a horizontal approach. The aim is improved SRH services through identifying best practices in delivering a combined package of interventions for general population women and female sex workers. The research will occur in Kenya, Mozambique, South Africa, and Mysore, India by a consortium of 3 African, 1 Indian and 2 European partners. Detailed situation and policy analyses will be conducted in each country, with key stakeholder and community participation, and will inform the design of context-specific interventions to be implemented as feasible and acceptable packages of interventions. We will apply health systems research methodology to evaluate effectiveness and sustainability, and to identify the determinants of successful, sustainable and replicable interventions. This project will help to define packages of SRH services and models for delivery that meet the needs of all women and impact positively on their health.