OBJECTIVES: Evaluate the budget impact to the public healthcare system in Brazil after introducing dienogest (2 mg) as a treatment option in detriment of GnRH analogues (GnRHa) for patients with endometriosis-associated pelvic pain (EAPP). METHODS: The analysis was conducted from the public perspective over a five-year time horizon. The budget impact model (BIM) specifically considered women with EAPP. A recently cost-minimization (CM) model developed for EAPP provided the estimates of average treatment cost in Brazil based on local guidelines. This CM model compared different treatment pathways for women with EAPP and used a 50% improvement in pelvic pain as a definition of a treatment response. A patient flow was developed based on epidemiological and demographical data. Based on market uptake assumptions, results from the CM model and the patient flow, the BIM estimated the incremental budget impact after adopting dienogest. The model assumed that during the first year, 6.76% of EAPP patients receive dienogest in detriment of GnRHa. After 5 years, it was assumed that dienogest would capture 30% of the GnRHa market in EAPP. RESULTS: Based on the patient flow developed approximately 0.52% of the population were estimated to be diagnosed with EAPP and receiving treatment with GnRHa. In the year after introduction of dienogest, the overall budget used to treat EAPP was estimated to decrease by up to 2.98% with the budget saving estimated to increase to around 12.98% by Year 5. CONCLUSIONS: This analysis portends that the budgetary impact of adding dienogest to the public healthcare system in Brazil, in detriment of the GnRHa, result in a budgetary cost saving alternative.