The sonographic findings observed in four patients with spontaneous rupture of a renal angiomyolipoma and perinephric haemorrhage are presented. In all cases, a hyperechoic renal mass surrounded by a large hypoechoic haematoma was identified. Furthermore, the actual site of rupture of the tumour could be seen in one case as a wedge-shaped hypoechoic structure extending from the periphery to the centre of the mass. CT has been suggested as the method of choice in the assessment of both the presence and extent of haemorrhagic complications of angiomyolipomas. However, since such lesions can be demonstrated and identified by ultrasound, which is often used as the first imaging procedure in abdominal complaints, the technique may also prove of value in planning further diagnostic tests and in choosing the appropriate therapeutic approach to these patients.