Background: Hysteroscopic endometrial ablation is increasingly accepted as a safe means of controlling excessive uterine bleeding. Case: A 47-year-old woman underwent endometrial resection and ablation for menorrhagia and subsequently developed pyometra and bacteremia. Placement of an intrauterine drain and intravenous antibiotic therapy led to full recovery. Conclusion: Postoperative pyometra occurred after endometrial resection and ablation, a procedure reported to have few complications. To our knowledge, this has not been reported before.