The purpose of this paper is to discuss development and use of procedures to e_valuate application of ~ovine Somat~tro~in (BST) with respect to profitability at farm level. BST remains a controversial product and uncertamty surroundmg its appropriateness as teclmology is increased by the fact that no Joe~) study in conn~ction with its profitability ~as been conducted previously. On-farm response trials at three representative case study sites and a personal t~lepho~uc survey conducted amongst existing users of BST provided a valuable basis to develop and apply a management s1mulahon model. The model and procedures of analysis are flexible and could be applied to other problems of dairy farm manageme_n~. Results indicated that, given the conditions of research, utilisation ofBST proved to be profitable. BST has the capab1hty to improve profitability of certain dairy businesses. The critical factors in determining profitability of ~ST utilisation, apart from management, are the milk price, response to BST as we11 as BST and feed cost. Milk production quotas may have a negative effect on profitability ofBST.