Thin blood smears were collected from 126 mammals representing four genera of marsupials and six genera of murid rodents. A species of Hepatozoon was discovered in the New Guinea spiny bandicoot (Echymipera kalubu), trypanosome infections were found in three genera of rodent hosts and the prevalence of a rickettsial parasite of the genus Grahamella was recorded in rodents from the genera Rattus and Melomys. Dried blood samples also were taken and screened serologically for antibodies to arenavirus infection but with negative results.