The evolution of 97 cases of epithelial dysplasia in the head and neck region was retrospectively controlled, with a mean follow-up of 30 months. Dysplastic mucosal areas were observed in the oral cavity in 11 cases, in the pharynx (oro- and hypopharynx) in 39 cases and in the larynx (supraglottic and glottic regions) in 47 cases. According to the criteria defined by the WHO the dysplasia was classified as mild, moderate and severe. Fifty out of the 97 patients developed a squamous carcinoma in the same area, demonstrating a significant direct correlation between age and neoplastic evolution. A direct correlation was also observed between severity of dysplasia and carcinomatous evolution. Further direct correlations were observed between degree of dysplasia, carcinomatous evolution and amount of exposure to cigarette smoke and alcohol.