Prunus africana (Hook f) Kalkman, a threatened medicinal tree of the Afromontane forest of Mount Cameroon, was studied with respect to population structure and aspects of the reproductive biology. Populations on Mount Oku and the Tchabal Mbabo areas were also characterised. There was considerable variation with latitude in the size class distribution. The size class distribution was more "balanced" on Mount Cameroon, the most southerly population considered for the study of the flowering phenology and the pollination biology. Prunus africana flowers are incompletely dichogamous, displaying an overlapping female -male sequence at anthesis. The longevity of a flower was 6-8 days and flowering within a raceme occurred acropetally. The flowering and fruiting sequences of individual trees showed that Prunus africana flowered and fruited periodically on Mount Cameroon from December to May. Flowering was irregular, with most individual trees not reproductively active and with those, which were producing flowers and fruits in only one of the two years of the study. Flowering synchrony indices of individual trees were high (up to 0.83) and the mean synchrony indices ranged from 0.25 to 0. 75. Estimates of floral productivity per flowering tree ranged from 4402 (dbh = 27 cm) to 730765 (dbh = 82 cm) flowers. Fruit productivity followed the same trend and the estimates ranged from 891 to 80493 fruits per tree. The mean number of flowers per unit of crown shadow - from 100± 144 m-2 to 2952±646 m-2 -and the number of fruit -from 16±11 m-2 to 261±76 m-2 -per unit of crown shadow increased significantly with the tree size. Outcrossing was the predominant breeding mechanism, although flowers were self-compatible. The source of pollen had no significant impact on the germination parameters of the resulting seeds. Flowers were visited by a number of insects at anthesis, but only members of the Cerambicydae, Lycidae, Apidae and Megachilidae potentially effected pollination.