Purpose of investigation: To review risk factors, clinical presentation, diagnostic methods, and histopathologic findings in 27 cases of endometrial cancer in polyps. Methods: A descriptive, retrospective study of 204 consecutive patients with endometrial carcinoma who were diagnosed at our institution between June 1998 to June 2001. Endometrial cancer arising in polyps occurred in 27 patients (13.2%) and accounted for 1.8% of 1,492 endometrial polyps diagnosed during this period. Results: Patients had a mean age of 62 years. All except one woman were postmenopausal. Three breast cancer patients were currently given tamoxifen. Metrorrhagia was the presenting symptom in 74% of cases, although 22% of patients were asymptomatic at the time of diagnosis. Ultrasonography performed in 22 patients showed images compatible with an endometrial polyp in 50% of cases, myoma in 5%, and inconclusive findings in 45%. The median endometrial thickness was 11 mm (range 4-33 mm). Diag­nosis was made by aspiration-biopsy in 13 patients and by hysteroscopic endometrial sampling in 13 (in one patient endometrial carcinoma was incidentally found in the surgical specimen). All patients were in FIGO Stage IA. Endometrioid carcinoma was found in 81.5% of cases. Retroperitoneal metastases were not found in 25 patients undergoing pelvic lymphadenectomy, nor neoplastic growth in the specimens of six polypeptomies performed during hysteroscopy. All patients are free of relapse after a mean follow­up of 30 months. Conclusions: Postmenopausal women with endometrial polyps diagnosed by ultrasonography should undergo directed biopsies under hysteroscopic vision. The present series confirms the good prognosis of endometrial cancer in polyps.