Hepatoblastoma is the most common malignant liver cancer in childhood, yet its etiology remains unclear. As an m6A methylation modifier, methyltransferase like 3 (METTL3) has an active methyltransferase domain that functionally participates in various tumor occurrence and development. However, little is known about how METTL3 polymorphisms affect the occurrence of hepatoblastoma. Here, we attempted to investigate the associations between METTL3 gene polymorphisms and hepatoblastoma risk in a seven-center case-control study. We genotyped four METTL3 polymorphisms (rs1061026 T > G, rs1061027 C > A, rs1139130 A > G, rs1263801 G > C) by TaqMan technique in 313 cases and 1446 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the contributions of these four single nucleotide polymorphisms (SNPs) to hepatoblastoma susceptibility. In single genotype analysis, we detected no significant correlation between these four polymorphisms in METTL3 and hepatoblastoma risk. However, in the combined analysis, the presence of 2-4 risk genotypes of METTL3 was associated with an increased risk of hepatoblastoma compared with that of 0-1 risk genotypes (adjusted OR = 1.48, 95% CI = 1.03-2.12, P = 0.035). The stratified analysis further revealed that carriers of 2-4 risk genotypes are more susceptible to hepatoblastoma in the subgroups of subjects aged under 17 months (adjusted OR = 1.88, 95% CI = 1.12-3.16, P = 0.016) and females (adjusted OR = 1.79, 95% CI = 1.06-3.05, P = 0.031). Overall, our results revealed that none of these four SNPs could increase susceptibility to hepatoblastoma individually. Carriers with 2-4 risk genotypes in the combined analysis tend to increase the risk of hepatoblastoma.