Basal cell carcinoma (BCC) is the most common cutaneous skin malignancy. BCC generally has a clinical course characterized by slow growth, minimal soft tissue invasiveness, and a high cure rate. Occasionally, however, BCC behaves aggressively with deep invasion, recurrence, and potential regional and distant metastasis. Several factors, including tumor size, duration, histology, and perineural spread, have been postulated as markers of the aggressive BCC phenotype. It is undetermined whether intrinsic biological factors within certain subsets of BCC predispose these tumors toward an inherently aggressive behavior, or whether any BCC with inadequate early management may assume this phenotype. Review of the pertinent literature on this topic suggests that both intrinsic biological factors and extrinsic management factors play a role in the development and progression of aggressive BCC.