© 2022, UHOD - Uluslararasi Hematoloji Onkoloji Dergisi. All rights reserved.Inflammatory processes play an important role in the pathophysiology of cGVHD. Serum fibrinogen is a proinflammatory protein with a wide range of functions in inflammation. But its role in GVHD is unclear. The aim of this study was to evaluate the predictive impact of pre-transplantation fibrinogen levels on cGVHD in allo-HSCT recipients. We retrospectively analyzed 249 patients with hematologic diseases undergoing allo-HSCT from 10/10 HLA-matched donors. Serum high fibrinogen levels at the time of HSCT (day 0) were significantly associated with cGVHD development in univariate analyses (OR 2.01, p= 0.012) and multivariate analyses (OR 1.003, p= 0.037). There was no significant association between fibrinogen levels and overall survival, disease-free survival and, acute GVHD (p> 0.05). This is the first report demonstrating the association between high fibrinogen levels and increased cGVHD occurrence.Further studies are warranted and may identify the efficacy of fibrinogen as a predictive marker on cGVHD in allo-HSCT recipients.