The effects on cell population kinetics in the distal esophagus of an apple brandy from Normandy (Calvados), of ethanol diluted at a similar concentration, and of saline were investigated in rats. Animals were killed at 0, 6, 12, 18 and 24 h after a single intraesophageal instillation, and at 3 weeks after chronic administration of these solutions. In vivo labeling with [<sup>3</sup>H]-thymidine and autoradiography were carried out to determine the proliferative parameters. Vincristine sulfate was used to increase metaphase figures during the chronic experiment. Instillation of saline did not modify the parameters under study. Single instillations of both apple brandy and 56° ethanol were followed by a significant increase in labeling (p < 0.01) and mitotic indices (p < 0.01). Chronic administration of both apple brandy and 56° ethanol increased the labeling index (p < 0.01) as well as the metaphase index (p < 0.01). The proliferative responses after the apple brandy and after 56° ethanol were similar in amplitude. These data suggest that ethanol alone may explain the mitogenic effect of Calvados in the esophagus.