The clinical features of a 9-year-old boy with an extra-adrenal phaeochromocytoma, complicated by malignant hypertension, are described. The value of urinary and blood catecholamine assays and specialised radiological investigations in the accurate localisation of the tumour, is emphasised. Successful removal of the tumour was facilitated by pre-operative control of the hypertension with a combination of alpha and beta-adrenergic blockade (phenoxybenzamine and practolol). Intra-operative control of fluctuations in blood pressure was simplified by the use of Ethrane (enflurane compound 347) as one of the anaesthetic agents. As a result, sodium nitroprusside was infrequently used.