A total of 1,512 women participated in mass screenings for uterine body cancer (UBC) from 1998 to 2003 at Tokai University Hospital. Their rate in the examinees of uterine cervical cancer (UCC) mass screenings was 4.7%. Among the 1,512 examinees, endometrial cytological abnormalities (class III or higher) were found in 17 (1.1%) cases. As a result, UBC was detected in two patients (0.13%). One case was diagnosed as class V, adenocarcinoma, and she underwent hysterectomy. In another case, adenocarcinoma was found to be associated with atypical endometrial hyperplasia in hysterectomy specimens. For the remaining 15 cases diagnosed as class III, the cytological abnormalities disappeared after a follow-up except for 3 patients who were not followed at Tokai University Hospital. In a comparison of the examinees with or without genital bleeding, the cytological abnormalities were more frequently detected in the former group; 4.2% (6/142) vs. 0.6% (5/819) (p < 0.05). We recommend examinees aged 40 years or higher with a complaint of genital bleeding to participate in UBC mass screening for detection of endometrial adenocarcinoma at early stages.