In this study economic weights for production and functional traits of the Holstein Friesians in South Africa were calculated using a simulation model. The production traits were milk, butterfat, protein and lactose yield and the functional traits included feed efficiency, survival rate, calving interval and live weight. The simulation model was developed for three production systems and made use of two South African milk price systems to calculate the economic weights. In both price systems the feed efficiency had the largest economic weight, followed by the four production traits. The economic weights of the other functional traits were much smaller than the economic weights of the production traits.