The diameter of the knots in every second whorl was measured in 26 trees of Picea abies (L.) Karst. in north-eastern France. The trees were of two French progenies, i.e. from the provenance La Ganne in Massif Central and from Morzine in the Alps. The trees were planted in 1970 with initial stand densities ranging from 200 stems ha-1 to 10 000 stems ha-1. The trees were felled and measured in 1997. Knot diameter was evaluated as mean diameter of the three thickest knots at different height intervals and as a vertical profile of the maximum knot diameter in each sample whorl. In all these cases, we found the knot diameter to be correlated with diameter at breast height. The additional effects of progeny and initial stand density were found to be significant, but slight compared to the effect of diameter at breast height.