Lately there is a tendency for an increase in the incidence of endometrial cancer both in this country and other industrialized countries such as the United States. The routine cervicovaginal smear method is generally poor for the detection of endometrial carcinoma as compared to that used for the diagnosis of early cervical neoplasms. The principal reason for the poor detection rate is that the cells are not obtained directly from the lesion as is the case with disease of the cervix. Various techniques for obtaining endometrial cells directly from the lesions have been described, but none has enjoyed wide acceptance by the clinicians. The patients for this study consisted of 138 women who were referred to us for diagnostic curettage. We employed the new disposable device, the Endocyte, and Masubuchi's endometrial aspiration and compared the results. After obtaining specimens with both methods curettage was performed on all patients. In addition, the Endocyte was employed on 8 patients with endometrial carcinoma in another hospital, and the following results were obtained. 1. With the Endocyte it is possible to obtain a larger volume of cells than by aspiration. 2. Although a certain amount of difficulty is encountered in the insertion of the Endocyte in some cases, it is much easier than the brush method used heretofore. 3. No significant difference in the amount of bleeding after insertion could be observed between the two methods. 4. In patients with bleeding in the endometrium and pyometra it is easier to obtain specimens from the endometrium with the Endocyte than by aspiration. 5. With the Endocyte contamination of the cells of the cervix was less than after aspiration. 6. Although pain during collection of cells with the Endocyte was somewhat stronger than during aspiration, analgesics were not necessary in any one of the cases. 7. The Endocyte was used on 13 patients with endometrial carcinoma, and all specimens were positive for carcinoma. From the results of our study we conclude that for endometrial cytology the Endocyte is as useful as the aspiration method. Furthermore, it should pose no difficulty to the gynecologists to use the Endocyte because the Endocyte resembles IUD structurally.