To data, epidemiological studies have assessed the association between peptidyl-propyl-cis/trans isomerase 1 (PIN1) gene polymorphisms and cancer risk, including breast cancer, hepatocellular carcinoma, lung cancer, esophageal cancer, head and neck squamous cell carcinoma, and laryngeal squamous cell cancer. However, the results of these studies remain controversial. We aimed to examine the associations between two SNPs (rs2233678 and rs2233679) of PIN1 gene and cancer risk by conducting a meta-analysis of case-control studies. A total of seven publications were included in this meta-analysis for both rs2233678 and rs2233679. Overall, rs2233678 polymorphism was found to be associated with decreased cancer risk in four genetic models (C-allele vs. G-allele: odd ratio (OR) = 0.73, 95% confidence interval (CI): 0.60-0.88; CC vs. GG: OR = 0.55, 95% CI: 0.36-0.84; CC+CG vs. GG: OR = 0.72, 95% CI 0.58-0.90; CC vs. CG+GG: OR = 0.58, 95% CI 0.38-0.89). However, the rs2233679 polymorphism of PIN1 gene did not appear to have an influence on caner susceptibility. In the subgroup analysis by cancer type, we observed that the PIN1 rs2233678 polymorphism was significantly associated with decreased breast cancer risk (C-allele vs. G-allele: OR = 0.73, 95% CI: 0.60-0.89; CC+CG vs. GG: OR = 0.71, 95% CI 0.57-0.89). Further subgroup analyses showed that the PIN1 rs2233678 polymorphism was associated with decreased cancer risk among Asian people (C-allele vs. G-allele: OR = 0.63, 95% CI: 0.51-0.79; CC vs. GG: OR = 0.44, 95% CI: 0.25-0.80; CC+CG vs. GG: OR = 0.63, 95% CI 0.50-0.79; CC vs. CG+GG: OR = 0.47, 95% CI 0.26-0.86). In conclusion, PIN1 rs2233678 polymorphism might be a potential biomarker for cancer risk among Asians, especially for breast cancer. Further large and well-designed studies are needed to confirm this conclusion.