OBJECTIVES: This study provides the results from a minimization costs model that compares the use of Dienogest with the use of GnRH antagonist in women with Endometriosis diagnosis in Colombia and Argentina. METHODS: We used a cost minimization model. The case base are women with endometriosis diagnosis in a 1 year time horizon. For the Colombian analysis we used a public perspective while in Argentina we used a social work perspective and a prepaid medical services perspective. The costs used in this model are direct costs and were obtained from some insurers of Colombian and Argentinean health system. The colombian treatment schedule is: 12-month use of Dienogest vs. 6-month use of the GnRH antagonist, and the Argentina treatment schedule is: 12-month use of Dienogest vs 6-month use of GnRH antagonist + 6-month use of supportive treatment (treatment schedule 1), or 12-month use of Dienogest vs 9-month use of GnRH antagonist + 9-month use of add-back treatment + 3-month use of supportive treatment (treatment schedule 2).     RESULTS: For the case base studied, we found that in Colombia the total treatment cost is US$986.19 with Dienogest and US$2855.57 with the GnRH antagonist. In the other hand in Argentina. The total treatment cost for the treatment schedule 1 is US$534.57 with Dienogest and US$881 with the GnRH antagonist from the social work perspective, and $490.75 with Dienogest and 812.21 the GnRH antagonist from the prepaid medical services perspective. The total treatment cost for the treatment schedule 2 is US$534.57 with Dienogest and US$1488.28 with the GnRH antagonist from the social work perspective, and $490.75 with Dienogest and US$1386.21 the GnRH antagonist from the prepaid medical services perspective. CONCLUSIONS: The use of Dienogest minimizes the total cost either in Colombia and Argentina from any perspective.