OBJECTIVES: To conduct a cost effectiveness analysis (CEA) comparing 3.75 mg 1-month (1M), 11.25 mg 3-month (3M) and 30 mg 6-month (6M) leuprorelin acetate formulations (LAF) in patients with advanced prostate cancer (APC) in Switzerland. METHODS: A CEA was performed from the payer perspective using a decision-tree model. Total treatment costs per patient per year and cost-effectiveness ratios (CER) were calculated. Clinical efficacy and safety data (serum testosterone <50ng/dl and adverse drug reactions /ADRs/) for LAF were obtained from randomized trials. Direct medical costs (drug, physician consultation and drug administration, and ADRs), reported as 2011 in Swiss Francs (CHF), were obtained from a Swiss healthcare database (Tarmed) and doctor interviews. We assumed a patient would visit the physician’s office a minimum of 12, 4 and 2 times/year when treated with 1M, 3M and 6M LAF, respectively. The modeled annual costs were extrapolated to the median survival time (3.1 years) of a patient with APC. One and two-way sensitivity analysis was conducted to check robustness of the model. RESULTS: In Switzerland, the annual cost associated with 6M LAF (CHF 3,320) was lower than that associated with 3M (CHF 4,411) and 1M (CHF 5,672) LAF. The lifetime costs of treatment with 1M, 3M and 6M LAF were CHF 16,349, CHF 12,715 and CHF 9,664, respectively (Discount rate=3%). Annual cost savings associated with the 6M formulation were 41% and 24% over the 1M and 3M formulations, respectively. 1M and 3M LAF were dominated with higher overall costs and lower effectiveness compared to the 6M formulation (CER=CHF 5,154/effectiveness). Sensitivity analysis confirmed the robustness of the results. CONCLUSIONS: Results suggest 6M LAF as a cost-effective strategy for treating patients with APC. Dosing frequency, reduction of possible local side reactions and number of outpatient visits could be potential factors in optimizing drug-related treatment costs for APC.