Preoperative ultrasonographic examinations of endometrial carcinoma have been performed in 47 patients in Tokushima University Hospital since 1976. The size of intrauterine echo masses, cervical involvement and thickness of uninvolved myometrium were measured by longitudinal and transverse scan. The results were compared with postoperative histological findings. The results were as follows; 1) Endometrial echoes were identified in 94% (44/47). Echogenic masses which were characteristic of endometrial carcinoma were observed in 79% (37/47). 2) The average size of echogenic masses in pT1 carcinoma was significantly smaller than in more advanced cancers (pT2 or more). Especially when the area (longitudinal x anteroposterior diameter) of a mass was under 500 mm2 and the volume (longitudinal x anteroposterior x transverse diameter) was under 10,000 mm3, the probability of pT1 carcinoma was significantly high. 3) Eighty-seven percent (13/15) of cases with and 81% (22/27) of cases without cervical involvement of endometrial carcinoma were correctly diagnosed by ultrasonography. 4) Extrauterine extension of the tumor was found in 63% (5/8) when the thickness of the uninvolved myometrium measured by ultrasonography was under 3mm, whereas when the thickness was over 3mm, extrauterine extension of the tumor was found in only 19% (5/27). From these data, ultrasonography was effective for the evaluation of the advancement of endometrial carcinoma, especially cervical involvement, myometrial invasion and extrauterine extension.