Background: Non-cystic fibrosis (CF) bronchiectasis is now identified more often than in the past. Objectives: It was the aim of this study to assess the high-resolution computed tomography (HRCT) localization and extent of bronchiectasis and to determine whether asthma status, atopy and bronchiectasis distribution are associated with the etiology of bronchiectasis. Methods: We retrospectively analyzed clinical, laboratory, functional and HRCT data of 105 children with non-CF bronchiectasis at 2 tertiary respiratory units in Italy. Forty cases had bronchiectasis associated with ongoing underlying conditions, namely primary ciliary dyskinesia, primary immunodeficiency or aspiration. Results: Age at the onset of chronic cough/wheeze and at the first X-ray-documented pneumonia as well as atopy prevalence were lower in patients with ongoing underlying conditions than in those without (p = 0.049, p = 0.003 and p = 0.0008, respectively). In most cases, bronchiectasis was multilobar, and a mean of 2.5 lobes were involved. The right side was more often involved than the left (88 vs. 70%; p = 0.002), and the upper lobes were relatively spared (p < 0.000001). Right lung involvement and multilobar disease were more prevalent in children younger than 2 years at first pneumonia (p < 0.05). Conclusions: Clinical information combined with laboratory data provides additional insights into the characteristics of non-CF bronchiectasis in a large population of Italian children. This study highlights the need for longitudinal evaluations, also using HRCT, of severe and non-resolving pneumonia in children.