We determined the effect of high doses of inhaled beclomethasone dipropionate (2000 micrograms day-1 for two weeks) on the glucose tolerance test, insulin levels, fasting cholesterol and triglyceride concentrations in fourteen normal and ten elderly diet controlled diabetic patients, in a single blind, placebo controlled trial. No significant disturbance of glucose or lipid metabolism was found in either group. This study suggests that at this high dose, BDP does not exhibit significant disturbance of glucose and lipid metabolism after two weeks use.