Background: Currently, the prognosis of bronchiectasis is based on different prognostic indicators, like BSI and FACED score, founded on clinical-demographic, functional and radiological criteria. Both scoring systems include the number of lobes involved in bronchiectasis, which represents an adverse prognostic index. Our study aimed to investigate the prognostic role of the clinical-functional parameters and the number of involved lobes ratio in adult bronchiectasis.Methods: The study was conducted on 52 patients diagnosed with non-cystic fibrosis bronchiectasis (NCFB) between 2015 and 2017 who attended the Pneumology Unit of Monaldi Hospital in Naples, Italy. Correlations between clinical-functional parameters (BMI, smoking history, number of exacerbations in the previous year, spirometry, DLCO, ABG test, and 6MWT) and number of involved lobes were investigated.Results: At baseline, the number of exacerbations in the previous year had a statistically significant association with the number of involved lobes. Furthermore, at baseline, the radiological criterion was also negatively associated with some functional parameters (FEV1/FVC ratio e FEF25-75%). Statistical significance was lost during the follow up, demonstrating the effectiveness of the therapy.Conclusions: Imaging extension represents a promising biomarker of disease severity as well as a helpful follow up tool for non-Cystic Fibrosis bronchiectasis (NCFB).