Economic values of 14 production and functional traits for Improved Valachian and Tsigai were calculated. Semi-extensive production systems with one lambing per year were simulated using a bio-economic model. The marginal economic value of a trait was defined as the partial derivative of the profit function with respect to that trait. The relative economic value expressed the percentage proportion of standardized economic value (marginal economic valuegenetic standard deviation) of a trait in the sum of the absolute values of the standardized economic values over all traits. Milk yield was of highest relative importance (26% and 32% in IV and T) followed by productive lifetime and conception rate of ewes (16% and 15% in both breeds). The relative economic values of conception rate of female lambs and litter size were 9% to 11%, of survival rate of lambs at lambing and till weaning were 4% to 7%. The economic importance of all remaining traits was less than 4%.