An epidemiologic survey among 538 young persons between 15 and 26 years of age in a high-risk area for esophageal cancer in the People's Republic of China revealed a high prevalence of esophagitis. Histologically confirmed very mild, mild, and moderate esophagitis was observed in 31.6%, 10.7%, and 1.1% of 354 male and 30.4%, 4.3%, and 1.1% of 184 female subjects. The prevalence of micronuclei in esophageal smears was assayed in a subsample to investigate its possible association with esophagitis and with risk factors for esophageal lesions. Of the 186 subjects, 2.7% had mild or moderate esophagitis, 19.9% had very mild esophagitis, and 77.4% were normal. The frequency distribution of micronucleated cells in the esophageal mucosa was similar for the three diagnostic groups. Mean percentages of micronucleated cells did not differ by diagnosis of esophagitis, household status, current smoking status, presence of oral leukoplakia, or consumption of burning hot beverages or fresh fruit. Higher mean percentages were observed in the older age group of both sexes, but the difference was not statistically significant. The results suggest that if esophagitis is considered an important precursor state in the development of esophageal cancer, the scoring of micronuclei does not appear to be an efficient test for mild forms of esophagitis.