We describe a child with a localised pelvic neuroblastoma and a hypertensive crisis during the first weeks of life due to elevated systemic norepinephrine of tumoural origin. In spite of treatment with high doses of alpha-blockers, blood pressure did not respond fully and the boy had a very unstable circulation. Surgery was performed at one month of age. Adenosine, a potent short-acting vasodilator, was used for peroperative blood pressure control to protect the patient from an uncontrolled hypertensive crisis. During tumour manipulation the child became hypertensive with systolic pressure exceeding 130 mm Hg and adenosine infusion (100 micrograms.kg-1.min-1) was started with a prompt normalisation of the blood pressure. Adenosine infusion could be discontinued after tumour removal. Norepinephrine, dopamine, homovanillic acid and vanillylmandelic acid in urine were elevated preoperatively and normalised at follow up. Plasma concentrations of norepinephrine and dopamine were elevated preoperatively. Norepinephrine increased during hypertension due to tumour manipulation. Plasma neuropeptide Y increased during tumour manipulation but still within the normal range for infants. It is concluded that adenosine can be used peroperatively in children with severe hypertension and in this case no adverse effects of adenosine were noted. Furthermore, tumour synthesis and systemic release of norepinephrine, but not neuropeptide Y, contributed to hypertension in this child with neuroblastoma.