As cystic fibrosis (CF) is diagnosed in childhood, it is important that patients are educated from an early age on the importance of their diet and on the application of enzymes. The Royal Victoria Infirmary Trust employs a paediatric dietitian to provide dietetic advice to patients with CF and their families. The aim of this study was to investigate basic nutritional knowledge and enzyme usage of a small group of children aged 10–16 years with CF, who regularly attend the Regional Cystic Fibrosis Clinic at the Royal Victoria Infirmary as outpatients. The results from two questionnaires demonstrated that a reasonable background of knowledge existed across the sample. However, there were many examples where basic questions were unanswered, and perhaps more importantly, there was a lot of confusion about enzyme application. Whether this lack of knowledge directly contributes towards adverse levels of health in individual patients was outside the scope of this study. It is intended that future work in this area will examine the hypothesis that lack of nutritional knowledge is a contributory factor to poor patient health.