Abstract This paper reviews the current evidence base regarding efforts to overcome constraints to effective health service delivery in low and middle‐income countries. A systematic literature review was chosen as the approach to gather and analyse existing knowledge about how to improve the ‘close‐to‐client’ health system. We focused on three levels of constraints: community and household, the health services delivery level itself, and health sector policy and strategic management. In total, 116 studies were reviewed and their main findings presented. The results should be interpreted with caution due to the considerable limitations in the existing evidence base. Copyright © 2003 John Wiley & Sons, Ltd.