A middle-aged man was admitted with worsening hip pain, fevers and reduced mobility. These symptoms were preceded by a mechanical fall but despite regular analgesia, symptoms did not resolve. His prior medical history included ischaemic heart disease, hypertension and hypercholesterolaemia. A trauma and orthopaedic review revealed a painful left hip with reduced range of motion. In addition, some mild tenderness in the left iliac fossa was noted. Blood tests revealed markedly raised inflammatory markers. Plain radiographs and ultrasound were normal. MRI scan found a massive left iliopsoas collection secondary to perforated diverticular disease of the sigmoid colon. The patient was managed with intravenous antibiotics and the collection was drained percutaneously. Approximately 500 mL of pus was aspirated. The patient made an excellent recovery with interval imaging showing a reduction in the collection size.