Objective: Besides its hematopoietic function, erythropoietin (EPO) may protect tissues from degenerative disorders. As such, EPO and itsreceptors were revealed in nonhematopoietic cells, including stromal and endometrial epithelial cells. However, the role of EPO in endometrialdisorders is still unknown. Here, we aimed to examine the role of EPO and its receptor activation in the development of endometriosis in rats.Material and Methods: Animals were treated with EPO, darbepoietin (the synthetic form of EPO) or EPO’s receptor activator, methoxypolyethylene glycol-epoetin beta (MIRCERA), after development of endometriosis. Endometriosis was induced by estrogen-administrationfollowing surgical attachment of endometrial surface on the inner abdominal wall. Treatments were started 3 weeks after induction ofendometriosis and continued for the following 3 weeks. For the analysis of recurrence of endometriosis, additional analyses were conducted 3weeks after cessation of treatments.Results: As compared with vehicle-treated animals, lesion size was reduced significantly and recurrence of endometriosis was not observed inall treatment groups. Histopathologic examination revealed that EPO and darbepoietin were more effective than MIRCERA- and vehicle-treatedanimals.Conclusion: Here we provide evidence that EPO is a promising candidate for the treatment of endometriosis. Our histopathologic results inparticular indicate that EPO is more effective than its receptor activator MIRCERA in the development endometriosis. (J Turk Ger Gynecol Assoc2019; 20: 41-6)