Objective: Evaluation of the feasibility and usefulness of cytological analysis of the distension fluid used during diagnostic office hysteroscopy in patients with suspected endometrial pathology. Methods: In 243 consecutive patients undergoing diagnostic hysteroscopy for suspected endometrial pathology a few milliliters of the distension medium used for uterine visualization were collected and sent for cytological analysis. Findings of these "endometrial washings" were compared to visual hysteroscopic impression, endometrial biopsy and uterine histology - when available. Results: Endometrial washings were considered adequate in 227 patients (93.4%). In 12 cases (5.3%) atypical cells were detected: all of these presented either atypical complex hyperplasia or endometrial cancer at the final histological evaluation of the uterus. Four of the 16 (25%) patients diagnosed with endometrial cancer or atypical complex hyperplasia at the final histopathological analysis of the uterus had inadequate washings. No patient with cancer or atypical hyperplasia had negative cytology. Conclusions: Collection and analysis of the distension fluid is feasible and, when positive, has a remarkable value in the diagnosis of endometrial cancer and its precursors