To determine the long-term outcome of congenital cystic adenomatoid malformation (CCAM), the records of all patients with CCAM treated in three Hungarian paediatric surgical centers between 1977 and 1996 were reviewed. Patients were followed for up to 20 years following diagnosis and treatment. In 20 patients CCAM was diagnosed postnatally and in 3 prenatally. Biodata including the operative procedures are presented. Follow-up findings between 18 months and 20 years after diagnosis showed better height and weight growth in patients operated upon in later childhood compared with those operated upon in infancy. The older the patient at the time of diagnosis, the better was the long-term outcome.