Objective: Chronic lymphocytic leukemia (CLL) is a neoplastic disease that influences B cell lymphocytes. CLL is the most common kind of leukemia accounting for approximately 30% of all hematological malignancies. The functions of MTHFR enzyme are a critical juncture in the DNA synthesis, and in methylation of metabolic reactions. Two common genetic polymorphisms, C677T and A1298C, are associated with reduced enzyme activity. We evaluated the association between MTHFR gene polymorphisms and the CLL risk.