We have examined telomerase activities in uterine cancer specimens including non-cancerous normal counterparts by the method of TRAP assay. We detected strong telomerase activities in 29 of 30 cervical cancers (96.7%) and all 16 samples of endometrial cancer. Normal cervical epithelial tissues obtained from 5 individuals had very little telomerase activity but were evaluated to be diagnostically negative in the activity. In contrast, normal endometrial tissue specimens (4 out of 6) had relatively stronger telomerase activities in consistent with the result reported previously by others. Most notably, we found that dysplastic lesions in the uterine cervix had significant telomerase activities. In an attempt to examine the telomerase assay by using cervical scraping samples, we have detected the telomerase activity in one case of 12 (8.3%) normal cervical epithelia, one of 16 (6.3%) cervical dysplasias and 6 of 9 (66.7%) cervical cancers (stage 0-1b). These present study shows that the telomerase assay is useful for the diagnosis of cervical cancers. However, it is hampered to evaluate whether or not telomerase activity in endometrial cancer specimens is attributable to cancer cells because of the presence of relatively strong telomerase activity in normal endometrium. In addition, telomerase activities was detectable in scraping samples from uterine cervix which were clinically diagnosed as CIS but not dysplasia and normal.