BACKGROUND Giant basal cell carcinoma (GBCC) is a tumor ≥5 cm in size, with aggressive biological behavior, that represents 1% of basal cell carcinomas (BCC), and studies regarding it are scarce. Our objective was to investigate the clinical-histopathological characteristics of GBCC and the risk factors associated with its development. METHODS A retrospective study over 8 years included patients with the clinical and histopathological diagnosis of GBCC. Age, sex, localization, size, evolution time, risk factors, and histological variants were compared to conventional BCC. Descriptive and inferential statistics were used, and a value of P < 0.05 was considered statistically significant. RESULTS Of 5958 patients with BCC, 115 (2%) of them corresponded to GBCC. The average patient age was 73 ± 11 years, and the male sex (52%) and localization on the head and neck (63%) predominated. Average tumor size was 6.6 ± 2.2 cm, evolution time was 96 ± 86 months, and high-grade histological variants (51%) predominated. The group with GBCC had higher age (P < 0.01), greater frequency in the male sex (P = 0.01), longer evolution time (P < 0.01); a greater prevalence of risk factors (24% vs. 16%, P = 0.01), antecedents of other types of cancer (P = 0.03), and of burns (P = 0.03); and a greater frequency of high-grade histological variants (51% vs. 29%, P < 0.01). CONCLUSIONS This is the largest series of GBCC published to date. Findings are similar to those previously reported, although the prevalence found here was greater.