Sera from 27 captive and 132 free-living mammals in Kenya were tested for antibodies to Toxoplasma by the Sabin-Feldman dye test. Of these 8 of 8 (100%) captive carnivores, 14 of 19 (74%) captive herbivores, 11 of 14 (79%) free-living carnivores and 97 of 118 (82%) free-living herbivores were found to have Toxoplasma antibodies. The feeding and drinking habits of the various herbivore species were considered as possibly facilitating exposure to Toxoplasma oocysts; also the feeding on prey in the wild and on meat in captivity as favoring exposure to the cyst form of Toxoplasma.