An outpatient diagnositc technique comparable to the Papanicolaou smear for carcinoma of the cervix is needed to permit early recognition of adenocarcinoma of the endometrium. Five different techniques of sampling the endometrial cavity were carried out on 1, 742 patients at the University of Michigan Medical Center. A total of 2,553 specimens were correlated with operating room curettings to assess the accuracy of each sampling technique. The methods of saline irrigation with an antrum cannula, endometrial brush sampling, high-vacuum aspiration, and the Gravlee jet washer proved not to be accurate enough to be used as a routine screeening test. There was excellent correlation (96 per cent) between endometrial biopsies and curettings. In our experience, endometrial biopsy with a suction or basket curette was the diagnostic technique short of curettage which permitted accurate diagnosis.