In 11 children (aged 5-18 years) with end stage chronic renal failure, the effect on plasma potassium of two doses of salbutamol (separated by two hours) given intravenously (4 micrograms/kg) and on a separate date, of salbutamol administered by nebuliser (2.5 mg if the child weighed below 25 kg, 5 mg if above) was observed. Within 30 minutes of the first dose, the mean plasma potassium concentration fell significantly by 0.87 and 0.61 mmol/l after intravenous and nebulised administration respectively. Sixty minutes after the second dose the plasma potassium was significantly reduced by a further 0.28 and 0.53 mmol/l respectively. There was a significant difference between the two methods of administration at 300 minutes after the first dose favouring nebulisation. No major side effects were observed. Nebulised salbutamol should be the first choice emergency treatment of hyperkalaemia.