Strategic planning and strategic plans have gained popularity in the public sectors, including the health sector. However, the factors that facilitate and constrain the achievement of strategic planning outcomes have remained key research questions in the public sector and the health sector. From the perspectives of the council health managers, we explored the factors that facilitated or constrained the achievement of strategic results set out in the 2015–2020 Health Sector Strategic Plan in Tanzania Mainland. We conducted a qualitative study using a purposive sample of 15 council health managers from 15 councils in Tanzania. Qualitative data were collected using semi‐structured interviews. We analysed our data using a thematic analysis approach. Our study found facilitators and barriers to achieving strategic health sector results grouped under five domains: resources availability; management, leadership and governance; strategic collaboration and joint working with implementing partners (NGOs); community factors; and recent reforms in the health sector. Our study has generated insights into factors that facilitate or hinder the effective achievement of strategic health sector results at the council level. The Ministry of Health, the President's Office‐ Regional Administration and Local governments, and health sector development partners should timely provide funds, human resources, health commodities and medical equipment to councils, strengthen health management and leadership at the council level, ensure health education is provided to the community members on health services.