Background: Reports linking high pancreatic enzyme dosages with bowel stricturing in children with cystic fibrosis (CF) led us to review our policy for pancreatic enzyme supplementation. Methods: Twenty-five prepubertal children with CF, aged 3-10 years, underwent a programme of pancreatin reduction. They were encouraged to decrease their enzyme intake by matching their pancreatin dose more closely to fat intake. Patients were reviewed at regular intervals by a paediatric dietician who promoted nutrition aiming for an energy intake of 120-150% of the estimated average requirement (EAR) and > 120% of the upper reference nutrient intake (URNI) for protein. Growth during the 12 months prior to enzyme restriction was compared with the subsequent year's growth. Results: The initial mean pancreatin dose of 26 446 uLipase kg-1 day-1 (range 7305-53 088) was reduced to 12 583 uLipase kg-1 day-1 (range 4705-32 051). Growth was sustained on the lower enzyme dose (mean height velocity: 5.75±1.1 cm yr-1 vs. 6.12±1.4 cm yr-1, P> 0.05). There was a small but significant improvement in mean weight gain post pancreatin reduction (3.14±1.5 kg yr-1) compared with the preceding year (2.12±1.1 kg yr-1, P< 0.01). Nutritional analysis, including a 3-day food diary and measurement of nutritional indices, showed that energy, protein and micronutrient intakes were maintained. Children were not forced to alter their intake of dietary fat by the reduction in pancreatin dose. Conclusions: A substantial reduction in pancreatin dosage can be achieved without an adverse effect on either growth or nutrition.