Developing capacity in civil society organisations to improve access to HIV services and reduce vulnerability among key populations. Supported by a grant from the Centres for Disease Control and Prevention under PEPFAR’s Local Capacity Initiative, Nirantar developed capacity in 150 civil society organisations (CSOs) that run government-funded Targeted Interventions (TIs) for key population (KP). The TI programme interventions increase uptake of KP-responsive services, develop KP leadership, and expand advocacy and innovation to create an enabling environment to reduce violence against KPs and improve their overall wellbeing. Nirantar programme was implemented in the underserved Indian states of Chhattisgarh, Madhya Pradesh, and Odisha to create enabling environments for vulnerable key populations (KPs) – female sex workers (FSWs), men who have sex with men (MSM), transgenders, people who inject drugs (PWID) – to improve HIV prevention outcomes Nirantar sensitized health and non-health service providers to KP needs and strengthens programme CSOs through learning transfer from experienced implementers. The programme identifies legal and policy barriers that inhibit access to services for key populations, and working in close coordination with the health department and government, develops innovative strategies to remove these barriers. Community priorities were taken up by state-level advocacy coalitions established by Nirantar comprised of CSOs working for and led by KPs to advocate against stigma, violence, and policy-level gaps. The programme also generated quality operational data to enhance capacity development and inform policy advocacy to improve CSO performance towards a more engaged and impactful national HIV response for KPs.