Tropical medicine's fundamental task is to improve health in the tropics. By adopting primary health care strategies, it satisfies the real needs of the population while doing research, improving its effectiveness and social impact. We illustrate this with some examples drawn from our experience, where this potentiation is evident. A sanitary dermatology study, based on health auxiliaries and promoters, encompassed a whole jungle province, with 68,977 km2 and 103,681 inhabitants. It resulted in an excellent relationship with the populations, and findings of significance for early diagnosis and control of hanseniasis and other diseases. It also facilitated an extension of activities to include the entire Amazonian Region, with specific concentration on training of the health personnel. Clinico-epidemiological studies on leishmaniasis in Andean valleys incorporated activities of sanitary education, health care, aspects of community development, etc., and extended into other geographic areas. Migrant workers from high-altitude communities in Cusco who have been to the jungle and acquired cutaneous or mucocutaneous leishmaniasis formed Patient Associations. The latter now receive support for their health and development needs from health authorities and many institutions; our Institute contributes with improved therapeutic procedures and further epidemiologic studies to orient preventive and control measures.