ABSTRACT. Previous case-control studies having investigated the relationship between the X-ray repair cross-complementing group 1 (XRCC1) Arg194Trp polymorphism and thyroid cancer (TC) have drawn inconsistent conclusions. The current study aimed to clarify the role of this polymorphism in susceptibility to TC. An up-to-date search of PubMed and Web of Science databases was conducted, including articles published up to August 2015. Crude odds ratios (ORs) with 95%CIs were calculated to establish the association between the XRCC1 Arg194Trp polymorphism and TC risk. Five studies were used, comprising 911 patients and 1476 controls.