The Nigeria Hypertension Control Initiative (NHCI) launched a national treatment program in 2020, guided by the HEARTS technical package for cardiovascular disease prevention in primary care. This study presents a thematic analysis of key informant interviews with primary care experts from Abuja, Kano, and Ogun, exploring NHCI implementation experiences. Using a structured qualitative approach, we analyzed responses across four domains: service delivery, medication procurement and availability, task shifting, and broader program aspects. Findings highlight improvements in service delivery, medication access, task shifting, and health-seeking behavior. However, challenges persist, including incomplete training, user fees, administrative burdens, and logistical barriers such as transportation costs and stockouts. Despite these issues, satisfaction with the standardized treatment protocol was high. Task shifting was well-received, easing pressure on senior staff but underscoring the need for continued training. Recommendations include integrating diabetes care, decentralizing medication sourcing, and enhancing training to strengthen NHCI's efficiency and sustainability in resource-limited settings.