Yield was recorded on 87 on-farm breadfruit [Artocarpus altilis (Park.) Fosberg] trees of five major cultivars on Pohnpei Island during 1988. Cultivars varied in seasonality, growth form, and yield. Complementary seasonality between cultivars led to an extended fruiting season. Among tree-size attributes, canopy volume was the best correlate of yield, followed closely by trunk diameter at 1.3 m. Site elevation and soil pH were significantly related to total number of fruits set tree-1, but not the proportion of fruits dropped or harvestable yield. Total harvestable breadfruit yield unitÂ·1 of agroforest land was estimated to be 6.6 7 Â± 1.25 (95% CJ.) t ha-1 yr-1.