The susceptibility to carcinogens in the oral mucosa is increased with ethanol ingestion, causing genetic changes and development of dysplasia, leukoplakia and carcinoma. Proliferative activity is essential for oral mucosa homeostasis. Morphometric and immunohistochemical methods were used to investigate the hard palatine epithelium in ethanol-drinking rat strains (UChA and UChB). Thirty female adult rats aged 100 days were divided into three experimental groups: (1) Ten UChA (genetically low ethanol consumer) rats with voluntary intake of 10% v/v (< 2 g/kg/day) ethanol solution and water; (2) ten UChB (genetically high ethanol consumer) rats with voluntary intake of 10% v/v (> 2 g/kg/day) ethanol solution and water; and (3) ten Wistar rats with voluntary ad libitum water intake (control group). All rats received regular chow (Nuvital) ad libitum. Results showed epithelial hyperplasia in UCh rats, associated with basal, spinosum and granulosum cell areas and perimeter of cytoplasm and nuclei enlargement. Also, the height of the corneum layer was increased in alcoholic rats. Ki-67 and Caspase 3 expressions were higher in UCh rats. Chronic ethanol ingestion causes palatine mucosa hyperplasia associated with disruption of keratinization, which may enhance the susceptibility of the mucosa epithelium to the carcinogenic effect of agents like alcohol.