Bevacizumab is a humanized monoclonal antibody approved by the US Food and Drug Administration for use in combination with fluorouracil (FU)-based chemotherapy for first-line treatment of patients with metastatic colorectal carcinoma (CRC). Its mechanism of action is inhibition of tumor angiogenesis by neutralizing vascular endothelial growth factor. Adverse events resulting from its use include gastrointestinal perforation, wound-healing complications, hemorrhage, and arterial thromboembolism. We present a case of a 67-year-old man who developed Fournier's gangrene during treatment with bevacizumab 4 months after completing mFOLFOX6 (5-FU/leucovorin/oxaliplatin) for CRC. Other than bevacizumab, the patient had no medications and had no medical conditions that would predispose to Fournier's gangrene.