Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to be involved in the pathophysiology of some autoimmune diseases as systemic lupus erythematosus, ankylosing spondylitis, and multiple sclerosis. The aim of this study was to assess serum TRAIL concentration in systemic sclerosis (SSc) patients and to investigate its possible association with various disease parameters. Thirty SSc patients as well as 25 rheumatoid arthritis (RA) patients and 25 healthy volunteers were included in the present study. Organ system involvement in SSc patients was investigated. Pulmonary function tests as well as chest high-resolution computed tomography (HRCT) were done to detect pulmonary involvement in our patients. TRAIL concentrations were measured in the sera of SSc patients, RA patients and healthy controls by enzyme-linked immunosorbent assay. Mean serum TRAIL levels were significantly higher in SSc patients than in the control RA patients and in healthy controls (p < 0.001) while they were not significantly different between patients with diffuse cutaneous SSc and patients with limited cutaneous scleroderma. Serum TRAIL levels were significantly higher in SSc patients with pulmonary involvement and were significantly correlated with HRCT scores. Serum TRAIL levels are significantly elevated in SSc patients and are associated with SSc-associated pulmonary involvement denoting a possible role of TRAIL in the pathogenesis of SSc. Further studies may be needed to confirm these findings and the possible use of TRAIL in detection and possibly treatment of SSc-associated pulmonary disease.