Primary or idiopathic torsion of the greater omentum is an uncommon cause of acute abdominal pain, often mimicking other acute abdominal conditions. The diagnosis is usually made at laparotomy, with the presence of free serosanguinous fluid in the absence of any other intra-abdominal pathology being suggestive of this condition. Resection of the infarcted segment is the treatment of choice, offering rapid recovery and reducing the possibility of adhesion formation. We report a case of primary omental torsion and discuss the diagnostic and therapeutic implications of this entity.