Ten healthy volunteers received 10% intravenous fructose (0·5 g. per kg. body-weight per hour) for two hours following a one-hour control period in which physiological saline solution was infused intravenously. Blood-lactate rose significantly during fructose administration; and this change was accompanied by a fall in serum-bicarbonate and a rise in serum-glucose, which fell to hypoglycæmic concentrations an hour after infusion of fructose. Blood-uric-acid did not appreciably change; urinary urate excretion, urate clearance, and the ratio of urate to creatinine clearance increased during fructose infusion with no alteration of urinary pH. The lack of hyperuricæmia suggests that the hyperuricæmic effect of fructose previously reported is dose-related and associated only with larger than physiological concentrations of fructose infused under experimental conditions. While fructose seems to remain contraindicated in clinical settings where lactate accumulation must be avoided (diabetic ketoacidosis, hypoxia, postoperative period, and uræmia), it can be safely administered in physiological concentrations without fear of hyperuricæmia.