OBJECTIVES: We performed a pharmacoeconomic evaluation of LHRH agonists (LAs) in treating metastatic prostate cancer compared to standard care, as identified in the literature and by clinical experts, including: estrogens (DES), orchiectomy, antiandrogens (AAs), and combinations therapy (LAs+AAs). METHODS: A Markov model was constructed to perform a cost-utility analysis (CUA) over 5 years, from a Canadian provincial healthcare payer perspective. Treatment efficacy was determined by meta-analysis of published clinical data, and utilities were derived from the literature. RESULTS: In the base case analysis, DES was least costly ($588) but also least effective (0.52 QALYs). Orchiectomy ($830 for 0.92 QALYs), with an incremental cost-utility ratio of $615/QALY versus DES, dominated LAs ($8,116 for 0.75 QALYs) and AAs ($4,108 for 0.62 QALYs). Treatment with combination therapy was the most costly at $18,029 and the most effective (1.04 QALYs), with an expected incremental ratio $141,220/QALY versus orchiectomy. Changes in key variables in the sensitivity analyses did not affect the ranking of the treatment strategies, suggesting that the model was robust. CONCLUSIONS: LAs were dominated by orchiectomy in the base case analysis and most sensitivity analyses. Combination therapy displayed incremental cost effectiveness ratios over orchiectomy ranging from approximately $30,000 to over $100,000 per QALY. Orchiectomy was more effective, had fewer severe adverse reactions, and cost slightly more than DES, the least expensive treatment. However, due to potential psychological impact, further research is warranted to examine its acceptance by patients. Despite robustness, the utilities used in the model warrant further research.