We have presented a group of 70 patients over 25 years of age as of January 1, 1975, who were diagnosed as having cystic fibrosis (CF) at various ages from birth to 28 years. Some patients were diagnosed late in life in spite of classical symptoms and a characteristic history of the disease. Patients with CF present with a broad spectrum of symptoms which vary considerably in severity. This older age group represents approximately 10% of our current roster of patients with CF. This disease is no longer confined to early life and will continue to be seen with increasing frequency in older patients. Our experience with this disease indicates that a number of affected individuals can attain adulthood and find a useful place in society. The quality of life provided to these adults is illustrated in their intellectual, socioeconomic achievements and marital life. Our aim has been to recognize the disease as early in life as possible and to provide a comprehensive medical program which includes all aspects of health care.