BACKGROUND A keloid is a pathological scar hyperplasia that is affected by genetic and environmental factors. Although the involvement of cytotoxic granzyme B in keloids has been recognized, there is almost no research on granzyme B (GZMB) gene polymorphisms and keloids. This study aimed to explore the relationship between genetic polymorphisms of GZMB and postsurgical keloid susceptibility in the Han Chinese population. MATERIAL AND METHODS A total of 3078 participants, including 990 patients with postsurgical keloids and 2088 controls without postsurgical keloids, were enrolled. We selected 15 common DNA variants in the GZMB gene for analysis. Associations were analyzed in both single marker-based and haplotype-based methods. The Genotype-Tissue Expression database was used to examine the biological significance of the targeted single nucleotide polymorphisms (SNPs). RESULTS SNP rs8192917 was found to be associated with the susceptibility of keloids (t statistic=4.82, P=1.47×10⁻⁶). An increased risk of keloids was significantly associated with the minor allele (C allele) of rs8192917 (odds ratio=1.33; 95% CI=1.18-1.49], P=1.47×10⁻⁶). In addition, a significant association was reported for genotypes of rs8192917 and clinical severity of keloids (χ²=10.61, P=0.03). CONCLUSIONS The results suggested there are significant associations between common genetic variants in GZMB and the susceptibility of postsurgical keloids in the Chinese Han population. These genetic polymorphisms were also related with the severity of postsurgical keloid symptoms in participants with keloids. The current study can contribute to future etiological and clinical research of keloids.