Patients with common variable immunodeficiency (CVID) have impaired production of immunoglobulins and hence recurrent airway infections, which in turn may lead to radiological changes and impaired lung function. Uncertainty exists about the nature and frequency of the radiological and the physiological abnormalities, and how they relate to each other. We reassessed high resolution computed tomography (HRCT) images in 65 patients, reported results from previously measured lung function tests, and studied relations between radiology, function and clinical variables. Airway obstruction, ventilatory restriction and impaired gas diffusion was found in 40, 34 and 21% of the patients, respectively. HRCT abnormalities were present in 94% of the subjects, mild changes being the most common. Bronchial wall thickening, found in two thirds of the patients, was related to airway obstruction and impaired gas diffusion. Linear and/or irregular opacities, the most frequent interstitial abnormality, was related to impaired gas diffusion. Bronchiectasis was found in more than half, but only severe bronchiectasis was related to airway obstruction. Since bronchial wall thickening and linear and/or irregular opacities are both frequent and important determinants of impaired pulmonary function, more attention should be given to these features in the follow up of CVID patients.