Thoracic aortic dissection (TAD) is a life-threatening vascular condition, in which matrix metalloproteinases (MMPs) are involved. Since the key determinants underlying MMP action remain elusive, the present study investigated the correlation between single nucleotide polymorphisms (SNPs) in the promoter region of the MMP‑8 gene and a predisposition to TAD, by comparing genotypes of TAD patients and healthy controls. From 154 TAD patients and 148 healthy individuals, DNA samples were obtained from venous blood, and genotyping was performed by a combination of polymerase chain reaction and automatic sequencing to detect SNPs in the MMP‑8 promoter. Data were analyzed and odds ratios (OR) and 95% confidence intervals (CI) were calculated. P<0.05 was considered to indicate a statistically significant result. Two SNPs, -799C/T and -767A/T, were identified in the MMP‑8 promoter. Distribution of the -767A/T genotype was not significantly different between the patients and healthy controls. The -799C/C genotype was utilized as a match control, and significant differences in the genotypic distribution were observed between the patients with TAD and the controls. Furthermore, it was identified that the distribution of the ‑799C/T+T/T and -799C/C genotypes between the TAD and control populations was significantly different. The frequency of T allele distribution was higher in the TAD group (27%) than in the control group (13.5%). The genotype distribution followed the Hardy-Weinberg equilibrium. In the present study, it was concluded that the ‑799C/T polymorphism in the promoter region of MMP‑8 may be associated with the development of TAD and that the T allele may increase patient predisposition to the disease.