1. Aspects of the influence of predation on the African buffalo Syncerus caffer were studied in Lake Manyara National Park, northern Tanzania, from 1981 to 1985. 2. During the study period, predation by lions was the most important cause of death in buffalo but occasionally major epidemics, such as rinderpest, can be by far the most important cause of death. 3. A comparison of Manyara with four other areas in Africa shows that the Manyara buffalo ran the same level of risk as those in these other areas, and that in periods in which epidemics or drought conditions are absent it was normal that ultimately some 90% of the large herbivores fell victim to predation. 4. Juvenile mortality in females was higher than in males but adult mortality in females was lower than in males. Adult bulls ran a much higher risk to be killed by lions (12.9% p.a.) than herd-living buffalo (4.4% p.a.); the latter category comprised cows and sub-adult bulls. 5. Risk of predation was highest near the ecotone between grasslands and structurally closed vegetations. Grasslands were as dangerous as woodlands and thickets, and only the mudflats were really safe. The chance to be killed fell steeply away from (potential) cover for lions. 6. Buffalo were more vigilant at night than during the day, peripheral animals more so than central ones. Adult bulls were more vigilant than other categories of buffalo. It is concluded that vigilance in buffalo was not restricted to predator detection. 7. The choice of feeding areas in buffalo was not dictated by predation risk alone.