The prevalence of mild and serious nutritional disorders in patients with cystic fibrosis is high. One of the possible ways how to supplement the necessary nutrients is the administration of defined supplementary enteral nutrition. The objective of the presented work is to evaluate the effect of supplementary domiciliary enteral nutrition in adult patients with cystic fibrosis. To eight patients with cystic fibrosis, mean body weight 51.77 +/- 10.63 kg, mean age 24.7 +/- 1.9 years for a period of 6 +/- 1 months enteral nutrition was administered (containing 40 and 55.1% energy as fat) with a caloric density of 10 kcal/kg as supplementary domiciliary nutrition. The mean body weight increased from 51.77 +/- 10.63 to 53.13 +/- 10.59 kg (p < 0.02), the mean skinfold thickness increased from 7.98 +/- 6.04 to 8.65 +/- 6.30 mm (p < 0.05) and the mean serum albumin concentration increased from 33.66 +/- 0.97 to 37.29 +/- 3.33 g/l (p < 0.05). No undesirable side-effect associated with the administration of enteral nutrition were observed. The nutritional intervention by domiciliary enteral nutrition produced no undesirable side-effects and led to a statistically significant improvement of parameters of the nutritional status.