Pyometra is a very uncommon disease principally occurring in postmenopausal women. It is characterized by the accumulation of purulent material within the uterine cavity. This paper presents the clinical history of a 35-year-old premenopausal woman with otherwise normal menstruation who developed heavy menstruation and was diagnosed with a benign pyometra of indeterminate etiology in March 2017. The patient underwent repeated ultrasound-guided drainage, dilation and curettage, and antibiotic therapy.Biopsies of the pelvic sidewall revealed endometriosis in June 2017. The heavy menstruation and suppurative fluid in the uterus of the patient persisted in which intramuscular leuprolide acetate was prescribed to address the endometriosis and heavy menstrual bleeding.Ultimately, the leuprolide acetate effectively resolved the patient’s bleeding and pyometra. The medication was concluded after 12 months of supervision and the patient is currently symptom free. Pyometra is an unusual condition rarely identified in premenopausal women. Drainage and antibiotic therapy are routinely employed; however, one may consider gonadotropin-releasing hormone agonist medication to potentially confer a beneficial patient outcome in rare cases where endometriosis and bleeding are intractable.