This WHO module is addressed to health personnel responsible for malaria control at national and sub-national levels of the health care system. It requires some basic knowledge, but the main objective of this modules is to inform professionals of the basics and methods of operational research. Countries need experts who can undertake routine operational research on certain interventions for policy changes and to monitor trends in morbidity and mortality. This will therefore help health workers operating in different epidemiological and socio-economic circumstances understand the use and methods of operational research for decision making, monitoring and evaluation of malaria control activities. The module consists of two parts: the Learner's guide; and the Tutor's guide.