OBJECTIVES: To estimate the cost effectiveness of dienogest versus GnRH analogue (GnRH-a) for the treatment of endometriosis-associated chronic pelvic pain in Slovakia for 5 years time horizon. METHODS: A cost-utility Markov model based on results of randomized controlled trial (AU19) was adapted to a Slovakian setting.  The AU19 trial, which compared dienogest and GnRH-a (leuprolide) in the treatment of endometriosis-associated chronic pelvic pain over a 6 month period, showed no statistically significant differences in response rates. The dienogest annual relapse rate was derived from 52-weeks extension study, while relapse rates for the GnRH-a were derived from the literature. Local cost data was based on published price lists, clinical guidelines, product labels and expert opinion. QoL related utilities were derived from individual patient SF-36 scores from AU19 dataset. Effectiveness was measured in quality-adjusted life years (QALY). Time horizon was set at five years and a payers’ perspective was adopted. Discount rate was 5% per year for both costs and effects according to valid Ministry of Health (MoH) guidelines for health economic evaluation. Both one-way and probabilistic sensitivity analyses were performed. RESULTS: Dienogest showed that it was cost-effective compared to a GnRH-a, with an overall cost reduction of 426 € and a QALY gain of 0.069 per patient. Cost reduction was due to both the differences in the average drug cost during the two year period  and the average laparoscopy cost.  In probabilistic sensitivity analysis 92 % of simulations were below 18,000 €/QALY, which is the officially published threshold for willingness to pay in Slovakia. In 79% of cases dienogest treatment was dominant over GnRH-a. CONCLUSIONS: Dienogest is a cost-effective alternative to GnRH analogue for the treatment of endometriosis-associated chronic pelvic pain in a Slovakian setting in a five-year time horizon.