Stenosis of a renal artery by extrinsic compression is an uncommon cause of renovascular hypertension. In rare cases, this compression is due to the presence of fibres from the diaphragm or the psoas muscle. This aetiology should be considered when renal artery stenosis is observed in a young hypertensive patient without cardiovascular risk factors. Spiral CT scan is particularly useful for studying the relationship between the diaphragm and arterial structures. Once the diagnosis has been made, the treatment is surgical section of the fibrous tissues responsible for the compression.