The A allele of rs12803915 in premature mir-612 was found to be protective (GG vs. GA vs. AA; OR, 0.61; 95% CI: 0.42 to 0.88; p = 0.007) against ALL risk. The G allele of rs3746444 in the seed region of mature miR-499-3p was also found to be protective (AA vs. AG vs. GG; OR, 0.67; 95% CI: 0.49 to 0.91; p = 0.009). An association with rs10061133 in mir-449b was also identified (AA vs. GA+GG; OR, 0.52; 95% CI: 0.31 to 0.89; p = 0.012). Eight SNPs present in the six miRNA biogenesis pathway genes (TNRC6B, DROSHA, DGCR8, EIF2C1 or AGO1, CNOT1 and CNOT6) were also identified. This evidence concerns the gene DGCR8 and acute lymphoblastic leukemia.