Antler traits (length of the main beam, circumference of the main beam, coronet circumference, and the number of antler points) in roe deer Capreolus capreolus (Linnaeus, 1758) from a population in Casentino (Northern Tuscany) were examined for associations with genotypes at loci coding for enzymes. Significant associations were found only in yearlings. Individuals homozygous for the allele Mpi 120 had significantly larger antlers than carriers of other genotypes at Mpi. Individuals homozygous for Pep-2 100 had significantly smaller antlers than carriers of other genotypes at Pep-2. In adults the results were essentially the same, but only as a statistically insignificant trend. The data were interpreted in terms of one or more genetic components having a major influence on antler development only in yearlings. This corresponds with behavioural data suggesting that in adults antler size is not related to reproductive success, but in yearlings it is correlated with sexual maturity and the rate of being expelled from the home range of their mothers by territory holders. The situation in the roe deer was compared with previous results on the genetics of antler development in the red deer, where males are social rather than solitary, yearlings do not participate in reproduction, and some antler characteristics are related to reproductive success of adult stags.