BACKGROUND: Congenital diaphragmatic hernia (CDH) represents a chronic condition with significant pulmonary and non-pulmonary complications. The main aim of the present study was to determine the pulmonary outcome in a group of long-term survivors of CDH. METHODS: Clinical records of 46 patients with CDH admitted to the University Children's Hospital Zurich between 1991 and 2001 were reviewed retrospectively. Survivors underwent clinical examination, lung function tests and measurements of exhaled nitric oxide. RESULTS: 30 of 46 (65%) patients survived after repair of CDH and 19 children participated in a follow-up study at the mean age of 7.9 (2.8) years. At least one wheezy episode requiring inhaled bronchodilators was reported by 9/19 (47%) children and 4/19 (21%) children complained of recurrent wheezy episodes. Nine children showed lung function impairment in spirometry as well as in oscillatory resistance. Neither duration of assisted ventilation nor the length of hospitalisation appeared to correlate with lung function. Exhaled nitric oxide was within normal range in our group of CDH survivors. Measurement of respiratory system resistance using a forced oscillation technique detected those CDH survivors, who showed abnormal pattern in spirometry. However, no correlation between oscillatory resistance and specific airway resistance measured by whole body plethysmography was found. CONCLUSIONS: Despite the presence of rather insignificant symptoms, we found mild to moderate pulmonary functional impairment in children surviving CDH repair.