In Poland, cases of imported malaria are noted at present. In Polish citizens who work abroad, malaria is considered as an occupational disease. 95 cases of malaria in Polish citizens treated at the Clinic of the Institute of Maritime and Tropical Medicine in 1984-1993 were subjected to retrospective analysis, considering their occupational, epidemiological and clinical aspects as well as permanent sequelae of the disease. The most numerous groups among the patients examined were seafarers, fishermen, priests and missionaries. They were infected mostly in West Africa, during the first year of work. The majority of patients neglected chemoprophylaxis of malaria. In about 1/3 of patients, the resulting incapacity for work exceeded 1 month and more. In 7% of patients, 6 months after the treatment, permanent sequelae of the disease were observed: damage to the central nervous system, liver, kidneys and heart. The social and material costs of this invasive occupational disease were high. Malaria is an important health problem in Poles who work in endemic areas. Malaria prevention should be intensified.