439 sera of domestic animals and various number (150-500) of human sera of the Cape Verde Islands were examined for antibodies against Coxiella burnetti, Brucella abortus, B.melitensis, Listeria monocytogenes, Shigella dysenteriae, S.flexneri, S. boydii, S.sonnei, Campylobacter jejuni, C.fetus ssp. intestinalis, Yersinia enterocolitica, Toxoplasma gondii and Chlamydia of the PLT-group. It could be shown, that on the Cape Verde Islands there is to be counted with numerous zoonoses due to various microorganisms in man as well as in domestic animals. Q-Fever examination showed exceedingly high positivity of human sera (81.6%) and those of domestic animals (84.7%). One of the main reasons for the wide distribution of infectious diseases, especially diarrhoeal diseases such as Shigellosis, Yersiniosis and Campylobacter infections as well as Salmonellosis and Amebiasis on the Islands is the bad hygienic situation, an improvement of which as well as an intensification of research work, health education and a better medical care would be essential for the control of communicable diseases on the Cape Verde Islands.