Twenty one children with cystic fibrosis were advised to decrease their pancreatic enzyme supplement (PES) dose to less than 10,000 units lipase/kg/day. Mean PES dosage was significantly decreased in 15 patients from 18,380 to 8647 units lipase/kg/day. There were no significant changes in energy or fat intake, but there were significant increases in weight SD score, height SD score, and weight/height ratio.