The information regarding the types of malaria contracted by individuals who spent work periods in endemic areas was collected and processed by the authors, taking it out from the official reports on cases of communicable diseases. The data have been taken out from the reporting system in force till 15.12.1990. World epidemiological situation is briefly considered, the species of Plasmodium involved, the geographical areas responsible of infection, chemoprophylaxis and hospitalization period have been taken into account.