Reports on the association between the solute carrier organic anion transporter 1B1 (SLCO1B1) T521C polymorphism and methotrexate-induced hepatotoxicity in patients with malignancies are inconsistent. This meta-analysis evaluated the association between the SLCO1B1 T521C polymorphism and methotrexate-induced hepatotoxicity. We performed a systematic review of previous reports from the PubMed, Web of Science, and EMBASE databases, and a meta-analysis was conducted. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated to evaluate the effect of the SLCO1B1 T521C polymorphism on the occurrence of methotrexate-induced hepatotoxicity. In total, data from five studies including 465 patients were analyzed. Patients had received a high-dose methotrexate regimen (1-5 g/m2). The SLCO1B1 variant allele (C allele) carriers had a 1.9-fold higher risk of hepatotoxicity than wild-type homozygote carriers (TT; OR, 1.94; 95% CI, 1.14-3.31). This meta-analysis demonstrated that C allele carriers of the SLCO1B1 polymorphism had a higher risk of hepatotoxicity than patients with the TT genotype. The SLCO1B1 T521C polymorphism may be a useful predictor for methotrexate-induced hepatotoxicity in patients with malignancies.