For over 35 years the Thailand Wellcome Trust Major Overseas Programme has conducted research on tropical infections and nutritional deficiencies causing illness and death in poor populations in Asia and elsewhere in the developing world. This has changed the way lethal infections such as malaria and melioidosis are treated. We aim to make a real difference. To achieve this we intend to carry out research with patients, and in the laboratory, to understand these diseases and to discover and develop new and better ways of preventing, diagnosing and treating them, and, in the case of malaria, eliminating it altogether. In this way we will improve the survival, prosperity and quality of life of populations living in the developing world. To ensure continuous improvement in health we train local doctors, nurses and scientists, and we build new and appropriate research facilities. We believe in the power of research networks, and collaborate widely with research groups based elsewhere in the developing world. By producing evidence that is persuasive to policy makers and solutions that are affordable and implementable we aim not just to make health care advances, but to ensure that they reach those that can most benefit from them.