Background and aim: Genetic variations in solute carrier (SLC) genes are associated with liver diseases, and Kruppel-like factor 12 (KLF12) affects the b chain of hemoglobin. We investigated possible correlations of SLC and KLF12 polymorphisms with viral clearance (spontaneous and treatment-induced) and adverse effects in Chinese chronic hepatitis C (CHC) patients. Methods: We genotyped the single nucleotide polymorphisms in 525 CHC patients, 137 patients with spontaneous clearance, and 207 healthy controls. Three hundred fifty-seven CHC patients received recombinant interferon-alpha2b/ribavirin (IFN-α2b/RBV) treatment, and 175 patients were chosen for analysis of drug-induced cytopenia. All raw P-values were corrected by the Bonferroni method. Results: A higher rate of sustained viral response was detected in patients with SLC4A11 rs3810560 CC variant versus TT/TC variant (76.9% vs 59.2%; OR, 2.42; 95% CI, 1.06-5.56, P = 0.037 after adjustment), but there was no significant difference among different hepatitis C virus genotypes. RBV-induced anemia was independently correlated with SLC29A1 rs760370 AA genotype (OR, 2.90; 95% CI, 1.29-6.54, P = 0.010), and the severity of IFN-induced thrombocytopenia was related to GG genotype (OR, 4.98; 95% CI, 1.27-19.61; P = 0.021); the detected effects held true for HCV-2a patients but weakened in HCV-1b patients. A reactive increase in platelet count was closely associated with KLF12 rs9543524 TT variant. Conclusion: SLC4A11 rs3810560 polymorphism independently affected the sustained viral response rates in CHC patients, whereas SLC29A1 rs760370 and KLF12 rs9543524 single nucleotide polymorphisms correlated with treatment-induced adverse events. Clearly, the predictive power varied with HCV genotypes and the reason for genotype-dependent discrepancy was not fully understood.