Health information system (HIS) is defined as integrated efforts to, ‘collect, process, report and use health information and knowledge to influence policy making, program action, Sound health statistics are essential for health decision-making at all levels of the health system. Unfortunately, health information systems in most countries are inadequate in providing the needed management support and the current systems are therefore widely seen as management obstacles rather than as tools, therefore this book provides an assessment of the national health information system in Iraq, the structure and performance of this system, with recognizing the strengths, weaknesses and gaps, it also provide an assessment of the behavioral, technical and organizational determinants affecting the health information system performance.