The diurnal primate community of the Korup area of south-west Cameroon is rich in species and high in endemism. Two years monitoring in the Support Zone around Korup National Park have shown that, although all species of the original community are still present, Preuss' red colobus and drill, which were considered to be threatened in the early 1990s, have declined further and are probably facing local extinction. Densities of the crowned monkey also seem to have declined. Only mona and putty-nosed monkeys have an expanded distribution, and densities that are within the range of those reported from previous studies in the region. Although hunting is the most important cause of these declines, logging also appears to be having a detrimental effect. In logged forest group densities of chimpanzee, red-capped mangabey, mona monkey and red-eared monkey decreased between the two survey years, whilst remaining constant or increasing in unlogged forest. The frequency of associations of guenon species did not differ between logged and unlogged study sites, but encounters of associations of all four guenon species were only found in unlogged forest. We strongly recommend enforcement of anti-poaching activities inside the Korup National Park, and establishment of wildlife management in the Support Zone, as only a combined strategy can successfully guarantee the persistence of the wildlife of the region.