A long-term study was carried out in a group of 325 patients with cystic fibrosis (CF) aged 6 months to 34.5 years who lived in Czechoslovakia to December 31, 1988. Care for CF patients is concentrated in so called CF centres which are established mainly by children's clinics. The patients have been systematically examined both clinically and in the laboratory. There is a close cooperation with the department of rehabilitation. Special attention is paid to psychological and social problems of patients and their families. Care for patients older than 18 years is provided in the departments of internal medicine and respiratory diseases for adults. Due to a complex care coordinated by CF centres the mean age of surviving CF patients has kept on increasing and the quality of their life has been improving.