Creon 10,000 Minimicrospherestrade mark (Creon) 10,000 MMS) is a pancreatic enzyme formulation that contains smaller spheres of pancreatin in a 50% smaller capsule than conventional microspheres (Creon) 8,000). This three-centre study investigated the preference of cystic fibrosis (CF) patients for these products. In one centre, 72 h stool fat excretion and coefficient of fat absorption (CFA) were also compared. Fifty-nine patients with a mean age 10 years (range 3-17) took Creon 8,000 ms for 14 days and were then randomised to 28 days of Creon 8,000 ms followed by 28 days of Creon 10,000 MMS, or vice versa. Dosing was lipase for lipase according to the labelled declaration. At the end of the second treatment period, 51 of 54 patients who completed the study expressed a preference, with a statistically significant preference in favour of Creon 10,000 MMS (47/51; 87%) vs. Creon 8,000 ms (4/51; 7.4%; P<0.0001). Stool fat (g/day) and CFA (%) were measured in 24 patients at the end of each treatment period: the products were therapeutically equivalent (Creon 10,000: 8.4 g/day, 91.3% CFA; Creon 8,000: 6.7 g/day, 93.5% CFA). Both products were well tolerated. In conclusion, in CF children we found a clear preference for Creon 10,000 MMS compared with Creon 8,000 ms with no difference in fat absorption between the two products. Creon 10,000s smaller capsules are easier to take and should aid patient compliance.