Objective:This research aims to establish the prevalence, factors associated with the onset, and clinical and histopathological features of oral leukoplakia and erythroplakia, so that these data can contribute to the prevention of these lesions and, consequently, of oral cancer.Material and method:A retrospective study was conducted at a reference service of Universidade Federal do Rio Grande do Norte (UFRN) from 2000 to 2012. To verify the association of variables, Pearson's chi-squared test and Fisher's exact test (p ≤ 0.05) were used.Results:Among 6,560 investigated records, 54 cases were selected, of which 44.4% were male and 55.6% female, with mean age of 56.93 years. Regarding habits, 72.2% were smokers and 25% were alcohol users; 17.9% showed association of both habits. Oral leukoplakia lesions were the most prevalent (0.65%) and oral erythroplakia showed greater association with malignancy in the histopathological presentation (p = 0.001). Most lesions showed no symptoms (p = 0.004). The most frequent was oral leukoplakia in smoking women, with mean age of 57 years.Conclusion:Knowledge of associated factors and clinical characteristics of oral leukoplakia and erythroplakia is essential for establishing the correct diagnosis and treatment.