INTRODUCTION: Sigmoid volvulus (SV) is the most common type of colonic volvulus. In Tunisia, it is the second leading cause of colonic obstruction. The primary predisposing factors include chronic constipation and a high, wide mesosigmoid with a narrow root. Endoscopic detorsion and surgery are the standard treatments. The association with underlying cancer is rare but significantly alters the therapeutic approach. CASE PRESENTATION: We present the case of a 68-year-old patient with a history of prostate hypertrophy and chronic constipation who presented with abdominal pain, biliary vomiting, and distension. Imaging revealed a sigmoid volvulus without necrosis. During laparotomy, manual counterclockwise detorsion was performed, followed by a carcinologic resection and Hartmann's procedure. The patient had an uneventful recovery and was discharged on the seventh postoperative day. Pathological findings confirmed the presence of a mucinous adenocarcinoma of the sigmoid colon. DISCUSSION: Sigmoid volvulus is the most common type of colon volvulus, accounting for 50-90 % of cases. While SV is frequently encountered, the association with underlying sigmoid cancer is rare. To our knowledge, only five cases of malignant tumors presenting with SV have been reported in the literature. Detecting this association necessitates a change in operative technique, specifically towards a carcinological resection. CONCLUSION: Sigmoid volvulus is the most common type of colon volvulus. It is crucial for surgeons and radiologists to be aware of its potential association with underlying colon cancer. This awareness allows for adjustments in surgical technique, ultimately leading to improved postoperative outcomes.