Basal cell carcinomas (BCCs) represent one of the most common human neoplasias. The excellent prognosis of the diagnosed early lesions and the low metastasis rate are particularities that required the investigation of the mechanisms of carcinogenesis on these lesions. In this study we analyzed the proliferation rate for 53 cases of BCC in relation to the clinicopathological parameters of the lesions using Ki67, considered a true indicator of cellular proliferation. The results indicated statistically significant differences in Ki67 immunoexpression related to histological type and lesion stage. The highest Ki67 values were observed in the adenoid and morpheaform subtypes, and in advanced tumor stages. This aspects may be useful for stratification of lesions in terms of tumor aggressiveness.