In response to recent suggestions in the literature that plus-tree selection for yield in forest trees might in general be ineffective, the empirical information contained in 24 published reports was examined. It was found that progeny of plus-trees selected for yield traits tend to be faster growing than their controls. It is argued that this observed tendency is likely to be due at least in part to a response to selection. The reported values indicate that genetic gains of up to 15% in height and diameter growth, and up to 35% in volume per unit area, can readily be achieved through plus-tree selection. This is consistent with theoretical expectations. However, it should be emphasised that the amount of gain from any particular plus-tree selection system depends on the values of the parameters that determine the response to selection (selection intensity, genetic variance, heritability). In unfavourable situations, gain could be close to zero. © 1994.