There is no consensus whether zinc (Zn) supplementation is necessary in cystic fibrosis (CF). For assessment of the Zn status, serum Zn concentration is the only easy available method. It is, however age dependent. We compare the serum Zn levels of CF patients with earlier reported normal values. Serum Zn was determined in all new diagnosed CF patients and a second time 1 yr later. Data concerning fat-soluble vitamin status, cholesterol, albumin, pancreatic insufficiency, and genotype were collected. Thirty-two patients, median age of 1.21 yr, were included. Four were pancreatic sufficient. The median Zn concentration at diagnosis was 10.7 micromol/L (5-21.4), with a significant increase 1 yr later (median: 12.1 micromol/L [7,803-16,1]). An association of serum Zn with vitamin A (p < 0.03) and with vitamin E (p < 0.02) was observed. Compared to age-matched healthy controls, there is no significant difference in serum Zn concentration either at diagnosis or 1 yr later. Although it was demonstrated that steatorrhoea causes Zn loss, the serum Zn concentration in CF is not significantly different from healthy controls. The relation with vitamin Aand E points to the increased losses by steatorrhoea. Therefore, Zn supplementation is advised in persisting steatorrhoea.