Annually ten percent of Swiss people expose themselves to the risk of acquiring a tropical or cosmopolitic disease during travel to exotic countries. A systematic check-up of returning travellers is however indicated only for those with acute or recurrent symptoms or after a prolonged residence in a critical region. Febrile states should be considered medical emergencies. Investigations comprise routine laboratory tests (examination of blood film and feces for presence of parasites) complemented by special tests based on anamnestic and clinical criteria. Special attention is given to fecal analysis which has to be adapted to the search for specific pathogens (Bacteria, Protozoa, Helminths). Serologic tests are of increasing importance for the detection of parasitic infestation allowing for specific therapy in certain cases.