Common variable immunodeficiency (CVID) is the most frequent serious humoral deficiency manifested in adulthood in the form of acute and chronic respiratory infections which in most patients lead to respiratory failure. Retrospective analysis of 28 CVID patients was made. Mean age at time of diagnosis was 38.6 +/- 18.6 years. The time which elapsed from the first symptoms to determining the diagnosis was three times as long as that indicated in other studies, i.e., 14.1 +/- 10.2 years. Twenty-three patients (82.1%) had respiratory complications. Chronic obstructive pulmonary diseases, n=16 (57.1%), and bronchiectasis, n=10 (35.7%), were the most frequent types of lung damage. In addition, two patients (7.1%) displayed evidence of interstitial lung process. Morbidity associated with CVID can be reduced by early diagnosis and adequate dosage of immunoglobulins to minimise the occurrence and progression of lung damage.