Demodex cafferi causes a nodular skin disease in African buffalo (Syncerus caffer caffer) resulting in eczematous lesions in severely affected animals. Average prevalence in 193 animals was 28%, infection rates being highest in animals 1 to 3 years old and equal in both sexes. A granulomatous reaction occurred in the lumina of infected hair follicles with numerous mites developing in the follicles and associated sebaceous glands. The Demodex in buffalo probably is not transmitted to cattle.