The following study was conducted as part of a review of management systems at a Provincial Health Department (Kampong Cham Province) and a National Health Programme (National Immunization Program) in 2002-2003 in Cambodia. The aim of this paper is to identify, analyse and recommend those management system factors that are critical to the success of health management performance, with a particular focus on provincial management. The review has identified critical success factors associated with health management performance at the sub-national level that include a stronger role for effective human resource management in health sector reform, elevation of the status of planning in senior level management, and the development of a more comprehensive and transparent finance system. These success factors will position the provincial level of health management to respond more effectively to the reform challenges of administrative de-concentration and political decentralization that are currently underway across a range of government sectors in Cambodia.