Background: The purpose of this study was to investigate immunological risk factors associated with BS (Biliary Strictures) after LT (Liver Transplantation). Material/Methods: The study included 192 patients out of 273 adult liver transplantations performed from August 2005 to December 2012, with a radiological or surgically proven biliary stricture. About 35 potential risk factors for biliary strictures were studied. Results: A biliary stricture was diagnosed in 22.9% of transplants; the anastomotic type and the non-anastomotic type complicated the transplantation in 18.2% and 7.8% of cases, respectively. Six patients (3.1%) presented both of forms. Univariate analysis using logistic regression showed that preoperative serum bilirubin level >2 mg/dl (P=0.040), donor age >46 years old (P=0.007), positive crossmatch (P=0.007), product of donor age and preoperative Model for End Stage Liver Disease (DMELD) >710 (P=0.011), occurrence of acute or chronic rejection (P=0.004; P=0.003), and biliary leak (P=0.002) were all significantly associated with the development of biliary stricture. At the multivariate analysis, Primary Biliary Cirrhosis (PBC) (P=0.019), donor age >46 years (P=0.008), crossmatch positivity (P=0.001), and acute or chronic rejection (P=0.005; P=0.043) appeared to be the only variables independently associated with the development of a biliary stricture. Conclusions: Immunological risk factors (PBC, crossmatch positivity, acute and chronic rejection) emerged as being the most important variables associated to the development of biliary strictures after LT
