Assessing the presence and severity of bronchiectasis (BR) and mucoid impaction (MI) of the airways in cystic fibrosis (CF) is difficult by non-invasive methods. We hypothesized that scoring ultrafast computerized tomograms (UFCT) of the chest for BR and MI could be useful in detecting early lung changes in 28 patients with CF. To do this, UFCT scores were compared to established clinical and chest X-ray (CXR) scores. Results showed that UFCT scores correlated highly with clinical (r = 0.88) and CXR (r = 0.93) scores, and several pulmonary function tests. Regression analysis indicated that BR influenced clinical and CXR scores more than MI. Both BR and MI were found in all areas of the lungs without a major propensity for one region, although there was significantly more BR in the right upper lobe than the right lower lobe. In patients with CXR score greater than or equal to 21 BR was present in 8/9 and MI in 3/9, while in those with CXR score less than 21 UFCT showed BR in 19/19 and MI in 17/19. We conclude: 1) scored UFCTs correlate well with CXR and clinical scores; 2) BR influences clinical and CXR scores more than MI; 3) UFCTs detect BR and MI in CF patients with minimal evidence of pulmonary disease; and 4) CXR scores less than 21 reflect the presence of both BR and MI.