We report a case of rectus sheath haematoma (RSH) in a patient undergoing laparoscopic right hemicolectomy and anticoagulant prophylaxis of a pulmonary thromboembolism (PTE) with low molecular weight heparin. This pathological condition is rare and could be a cause of misdiagnosis in patients with acute abdominal pain. It can be a serious complication in the course of anticoagulant therapy. A rapid, correct diagnosis may lead to better treatment which must be timely, aggressive and ultimately curative. Our patient, with acute onset and swift worsening of his general condition, benefited from an immediate surgical procedure, with ligature of the epigastric artery stumps and drainage of the haematoma.