Objective. To assess the value of high-resolution computed tomography (HRCT) in determining the extent and significance of lung disease in children with antibody deficiency states. Materials and methods. Seventy HRCT scans performed on 37 children with various antibody deficiency disorders over a 5-year period were retrospectively scored using a previously described demerit scoring system (0-25 with 0 = worst, 25 = best). Points are subtracted from 25 with increasing severity of disease. The potential correlations between CT scores and clinical factors, including age at diagnosis, age at CT, type of immunoglobulin deficiency, length of respiratory symptoms before diagnosis, number of pneumonias before diagnosis, type, length and success of therapy, patient compliance and pulmonary function tests (PFTs), were assessed. Results. Of the 37 children, a demonstrated 22 abnormal scans (CT score ≤ 22). All nine demonstrated bronchiectasis with a lower lobe and right middle lobe predominance. Statistically significant correlations were seen between severity of lung disease (CT score) and length of respiratory symptoms before diagnosis (p = 0.01), success of therapy (P = 0.001) and PFTs (P = 0.0008). Of seven children who were followed with repeated scans, 4 of the 7 demonstrated CT scores which improved on high-dose intravenous immunoglobulin replacement therapy. Conclusion. HRCT is a useful adjunct to demonstrate the extent and severity of lung disease at diagnosis and during therapy. Correlation with clinical factors suggests a higher risk group needing more aggressive management.