Bleeding from enoxaparin is a recognized side effect; however, the formation of rectus sheath and retroperitoneal haematomas is a rare and potentially life-threatening complication. Patients may present insidiously and without symptoms; therefore, high clinical suspicion of a bleeding intra-abdominal haematoma should be suspected in patients with a combination of clinical and biochemical evidence of bleeding. Treatment is patient dependent and is either interventional or conservative in approach. Clinicians should be mindful when prescribing high-dose enoxaparin with further caution advised for at-risk patients.