The results are presented of a trial with coconuts, testing progeny of 104 unselected seed parents. The progenies of the best 5 per cent of the parents, selected on their phenotypic values, gave yields 14 per cent above the progeny population mean, indicating that mass selection is effective. There was considerable variation in breeding values between the palms tested, and a higher frequency of desirable genotypes could be isolated when the parents were selected on yield of copra rather than when they were taken at random. Prepotency in coconut palms is discussed. Leaf production of the young palms within a family, during the first 40 months of their growth, was correlated with the breeding value of the parent.