Background: The significance of tumor thickness is not clear in the prognosis of basal cell carcinoma. We aimed to identify the relationship between the tumor thickness and aggressive histopathological growth pattern in BCC. Methods: We retrospectively reviewed 85 primary BCCs of 82 patients and recorded the histological subtype, ulceration, perineural invasion, and thickness of the tumor. Tumors with infiltrative, micronodular, morpheaform and basosquamous features were classified as having an aggressive growth pattern. Results: The aggressive growth pattern was determined in 21 (26.9%) tumors with a mean tumor thickness of 2.19±0.71 mm (range, 0.9-3,40). The non-aggressive growth pattern was detected in 57 (73%) tumors and the mean tumor thickness was 1.76±0.87 mm (range 0.50-4.40 mm). There was a statistically significant difference in the mean tumor thickness between the tumors with aggressive growth pattern and non-aggressive growth pattern (p=0.033). Conclusion: Tumor thickness might have positive correlation with aggressive histological pattern. Measuring and reporting tumor thickness may be a more practical way to determine the pathological risk for BCC.