Various haematological parameters have been measured in a sample of wild African elephants from two game parks in Uganda. The results are compared with those of other authors for the African and Indian elephant and other mammals. No intersex differences were found to occur but calves (1–5 years) differed from the population as a whole in several respects. Some values varied with season and this may be attributed to the effect of dehydration during the dry season. A number of elephants from one of the parks had abnormally high red cell numbers and the possibility is considered that this may reflect an incidence of habitat induced cardiovascular disease.