Subserial examinations of the noncancerous esophagus from 86 autopsy materials (male 47, female 39) in Kagoshima Prefecture revealed epithelial dysplasia in 54 instances (63%); 32 males (68%) and 22 females (57%). Higher grades of dysplasia were shown in 17 males (36%) and 3 females (8%). Histologically a formation of the rete ridge-like elongation of basal epithelium was characteristically conspicuous in these materials. Tabacco and alcohol intakes were regarded as promoting factors of dysplasia. Distribution and severity of dysplasia around carcinoma were histologically examined on semiserial blocks in 100 surgical materials under the consideration of preoperative treatment. A coexistence of carcinoma with extensive dysplasia was found in 24 instances and that with multifocal dysplasia in 46. Multicentric in situ carcinoma was found in 19 patients. These in situ carcinomas were frequently surrounded by severe dysplasia and occasionally showed gradual transition to the latter. The lesion of invasive carcinoma sometimes did not show sharp demarcation from the surrounding mucosa, especially in cases of well differentiated squamous cell carcinoma. The results indicate that dysplasia plays a significant role on carcinogenesis of the esophagus as a precursor lesion.