Atherosclerosis is a chronic inflammatory disorder. Macrophage migration inhibitory factor (MIF) is a potent cytokine that plays an important role in the regulation of immune responses. Polymorphisms including five- to eight-repeat CATT variants ((CATT)(5-8)) and G-173C in the promoter region of the MIF gene are associated with altered levels of MIF gene transcription. The purpose of the study is to investigate the relationship between promoter polymorphisms of the MIF gene and the severity of carotid artery atherosclerosis (CAA). The severity of CAA was assessed in 593 individuals with a history of ischemic stroke by using sonographic examination, and the MIF promoter polymorphisms of these individuals were genotyped. The carriage of (CATT)(7) (compared to genotypes composed of (CATT)(5), (CATT)(6), or both), carriage of C allele (compared to GG), and carriage of the haplotype (CATT)(7)-C (compared to genotypes composed of (CATT)(5)-G, (CATT)(6)-G, or both) were significantly associated with an increase in the severity of CAA. We conclude that polymorphisms in the MIF gene promoter are associated with CAA severity in ischemic stroke patients. These genetic variants may serve as markers for individual susceptibility to CAA. (C) 2013 Elsevier Inc. All rights reserved.