Background: In patients with cystic fibrosis (CF), thoracic morphology and its role in respiratory function is conditioned by anthropometric factors, as well as by pathological changes. While the lungs are continuously monitored, examinations of potential thoracic cage adaptations to the disease are rare. Hence, the aim of this study was to investigate thoracic configuration, and its correlation to spirometry measures over time. Methods: In total, 344 high-resolution computed tomography (HRCT) examinations from 90 patients were assessed and analysed. Those results were subsequently related to spirometry measurements performed within the same period. Results: The cohort displayed no homogenous change in thoracic configuration over time, and correlation between thoracic area and spirometry variables could not be supported statistically. Conclusions: Although the current study included a larger cohort of patients with CF compared to previous studies on thoracic morphology, no patient group-specific changes in thoracic configuration were revealed. Furthermore, no correlations between structural findings and functional respiratory measurements were found.