he author gives a brief history of research in nematology of insects. He presents and discusses the principal finding in this discipline, regarding parasitism observed in insects in the neotropical region. Only the parasitic nematodes on the general cavity are dealt with, while nematodes of the medical and veterinarian types are excluded. A briel· account is given of parasitism caused by the following types of nematodes: Allantonematidae, Aphelenchoididae, Merm thidae, Oxyridae, Rhabditidae and Thelastomatidae. The cases of parasitism mentioned in the literature are reportd, but there are few. With the exception of Brazil, in the case of OXYUROIDEA, no country has had a continuing program of studies in this area. The influence of these nematodes on the host insects is discussed: reduction of fertility rate, sterility or mortality. The nematodes, being one of the factors limiting the growth of insect populations, can be used in certain cases in an integrated control program. Many cases of parasitism observed on Chrysomelidae and Nitidulidae (Coieopetera) in French Guyana are presented. The author concludes that our knowledge on the subject is very limited in the neotropical region, and thus a large field of studies remains open.