Parasitic diseases are cosmopolitan and may affect all the world population. They kill several million people every year. The migrations and tourism make that even tropical diseases can be frequently met outside their geographical distribution area. Except the arthropod-borne infections, the great majority of these diseases are in relation with the faecal contamination of soil, the general level of hygiene and the food practices. Malaria remains the first world parasitic disease in term of mortality. The strong fall of the amoebic endemicity is due only to the improvement of the methods of molecular diagnosis. The socio-political and climatic upheavals may result in a creeping extension of the geographical limits of many parasites.