practitioners are able to interprete their results or that they refer to a specialist. By some examples the problems and tendancies of the parasitological diagnosis of these diseases are briefly analyzed. As for the malaria, particular emphasis is laid on the importance of the blood examination until immunological techniques for the detection of antigenes can assure the continuation of the procedure. Unless there is no room for doubt, an examination must be repeated at the proper time. The same situation applies for the stool examinations for the detection of intestinal amebiasis and lambliasis. Taking into account the increasing resistance of P.falciparum to Chloroquin, the ST1 has introduced routine in vitro tests. Moreover, these routine in vitro tests play a more and more important role in the diagnosis of protozoa, e.g. leishmaniasis and trypanosomiasis. Techniques for special examinations like rectal biopsy, skin-snips, urine and blood filtration are briefly illustrated. Blood eosinophilia is often the only objective sign for a helminth infection. It could indicate either an invasion phase (mainly ascariasis, strongyloidiasis, fascioliasis) with or without Loeffler syndrome or helminths in an impasse (toxocariasis) or even helminths that are difficult to trace without appropriate laboratory techniques (strongyloidiasis, filariasis). A comprehensive anamnesis and a serological screening, which is now possible through the ELISA technique, are the basis for the diagnosis of these eosinophilia.