Thoracic multidetector computed tomography (MDCT) is essential for the detection of interstitial lung disease (ILD) in patients with systemic sclerosis (SSc). Thoracic MDCT assessment can reveal the presence of thoracic lymphadenopathies (LAP) whose signification remains uncertain. The purpose of the study was to describe the characteristics and to assess the significance of thoracic LAP in patients with diffuse SSc. We conducted a monocentric observational study on adult patients with diffuse SSc, and collected general patient and first thoracic MDCT characteristics, PET-CT and outcome data. Comparisons were made between patients with and without thoracic LAP. Forty-eight patients were included. There were 30 patients (62.5%) with an ILD and 23 (48%) with at least one thoracic LAP on the first MDCT assessment. Median number per patient of thoracic LAP was 3 1-8, with a mean size of 11.7 ± 1.7 mm, mainly located in right para-tracheal area (22.8% of the total number of LAP), right hilar area (20.3%), left hilar area (6.5%), and sub-carinal area (15.2%). PET-CT showed lymph node hypermetabolism in 11/15 patients (73.3%) with mean SUVmax at 4 ± 1.3. There were significantly more males (p = 0.002) and more patients exposed to silica (p = 0.001) in patients with thoracic LAP. ILD was significantly more extended according to Goh score (p = 0.03), and using semi-quantitative score for mixed ground-glass reticulation (p = 0.01) and global abnormalities (p = 0.03) in patients with thoracic LAP and ILD. Thirteen patients (27.1%) died during follow-up without significant difference according to the presence or not of thoracic LAP (p = 0.15). There was also no significant difference concerning immunosuppressive treatment initiation (p = 0.17). Thoracic LAP are common in diffuse SSc and are generally multiple, not bulky, moderately hypermetabolic, and located at the base of the mediastinum lymph node chains. Their presence correlates with the extent of ILD. In absence of ILD, thoracic LAP presence seems to be often explained by silica exposure. NA.