CyclinD proteins, the ultimate recipients of mitogenic and oncogenic signals, play a crucial role in cell-cycle regulation. CyclinD2, one of the cyclinD family, is overexpressed in T-acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia and involved in the pathogenesis of leukemias. Recent reports indicated that CCND2 polymorphisms are associated with human cancer risk, thusly we hypothesized that CCND2 gene polymorphisms may contribute to childhood ALL susceptibility. We selected the polymorphism rs3217927 located in the 3'UTR region of CCND2 to assess its associations with childhood ALL risk in a case-control study. A significant difference was found in the genotype distributions of rs3217927 polymorphism between cases and controls (P = 0.019) and homozygous GG genotype may be an increased risk factor for childhood ALL (adjusted OR = 1.84, 95% CI = 1.14 -2.99). Furthermore, this increased risk was more pronounced with GG genotype among high-risk ALL (adjusted OR = 1.95, 95% CI = 1.04-3.67), low-risk ALL (adjusted OR = 2.09, 95% CI = 1.13-3.87), B-phenotype ALL patients (adjusted OR = 1.78, 95% CI = 1.08-2.95) and T-phenotype ALL patients (adjusted OR = 2.87, 95% CI = 1.16-7.13). Our results provide evidence that CCND2 polymorphism rs3217927 may be involved in the etiology of childhood ALL, and the GG genotype of rs3217927 may modulate the genetic susceptibility to childhood ALL in the Chinese population. Further functional studies and investigations in larger populations should be conducted to validate our findings.