Over the past two decades, community participation has emerged as an important dimension within decentralised district healthcare systems. In Tanzania, initiatives to strengthen community participation have focused on the formation of the health committees. Studies have reported variations in the performance of the committees. An exploratory case study design focusing on two districts was adopted to explore the differences in practice of the health facility committees in a well‐functioning district and one that is not. In both study districts, the committees were in place. The most common activities of the health committees were assisting the clinic in day‐to‐day running. The health committees' influence on policy, planning and budgeting was limited. Managerial and leadership practices of the district health managers, including effective supervision and personal initiatives of the top‐district health officials coupled with incentives, are the major factors for the good performance of the health facility committees and the boards. Inadequate training and low public awareness affected the performance of the committees. A greater role in governance and oversight is essential for effective and meaningful health committees. To achieve impact, health committees will require adequate training on the following: roles and functions of the health facility committees and the boards; interaction between the committees and the communities and the health workers; development of health plans and budgets at the local and district level; and monitoring and tracking. Copyright © 2015 John Wiley & Sons, Ltd.