Rising living standards and an increasing awareness of the health risks of a diet high in saturated fats have led to strong consumer discrimination against animal fats. Additionally the surplusses of animal products in Europe suggest that more attention should be paid to the inputs in animal production, rather than solely increasing output. Improving the efficiency of lean meat production is therefore an important consideration in all meat animal systems. In 1976 Fowler, Bichard and Pease proposed the ‘biological indices’ lean growth rate and lean food conversion as selection criteria in pigs. These traits may be estimated as the product of growth rate (GR) or food conversion efficiency (FCE), and in vivo estimates of killing out and carcass lean proportions. However, in cattle and sheep the relatively low coefficient of variation of estimated killing out and of lean proportions, means that the biological indices are frequently dominated by GR and FCE. In such cases there may be little difference in response from selection solely on GR and FCE (Simm, 1983). The objective of the present study was to derive economic selection indices for terminal sire beef breeds, which might give appropriate economic weighting to the components of efficient lean meat production.