Abstract Fournier gangrene is a necrotizing soft tissue infection involving the perineum. We present a case of Fournier gangrene as the clinical presentation of perforated metastatic rectal cancer. The patient is a 78-year-old man in a nursing home who presented to our institution with necrosis and ischemia of the scrotum. After wide debridement of necrotic tissue and bilateral orchiectomy, computed tomography was carried out to investigate abnormal findings seen on his chest X-ray, which revealed multiple pulmonary metastases as well as a mass highly suspicious for a perforated rectal mass. Once stable, a diverting colostomy and biopsies of the rectal mass were performed, confirming the presence of a metastatic, poorly differentiated rectal adenocarcinoma. Albeit an unusual etiology of Fournier gangrene, this case highlights the rare but important causes of this deadly condition and teaches us to be cognizant of the variations in the presentation of colorectal cancer.