Twenty Kenyan patients with visceral leishmaniasis were evaluated for the presence of Leishmania donovani in their peripheral blood. Smears, cultures and hamster inoculations detected parasitaemia in 11, 10 and six patients, respectively, and at least one method detected parasitaemia in 15 patients (75%). The likelihood of detecting parasitaemia correlated with the density of parasites in splenic aspirate smears. It is apparent that parasitaemia with L. donovani occurs frequently in Kenyan patients with visceral leishmaniasis.