The relative economic importance of 18 production and functional traits for Holstein and Charolais sires used for mating in a dairy production system applying crossing with beef sires and in a cow-calf pasture crossbreeding system were calculated. Theseweights can be used to calculate selection sub-indices for ranking sires according to the expected profit from mating these sires in a particular system. It was shown that optimum economic weights differ according to whether dairy sires will be used in purebred or crossbred systems and whether beef sires will be used in crossbred dairy or crossbred beef production systems.