Inguinal hernia is a potentially occult common surgical condition. Its association with asymptomatic adenocarcinoma is uncommon. However, malignancy-associated perforation of the large bowel within an irreducible hernia is rare. We report a case of 78-year-old male presenting with a long-standing inguinal hernia with a 2-day history of irreducibility. Examination revealed a large left-sided irreducible inguinal hernia. Patient underwent urgent inguinal herniotomy, during which multiple perforations were noted in the sigmoid colon. Patient underwent Hartmann's procedure following bowel resection. Histology revealed a mucinous adenocarcinoma with extensive metastasis involving the resection margins. Elderly patients with long-standing inguinal hernia presenting with acute symptoms should be evaluated further for this rare but sinister diagnosis.