Mutations in the NADP+-dependent isocitrate dehydrogenase genes 1 and 2 (IDH1 and IDH2) have recently been found in adult acute myeloid leukemia (AML) patients with a prevalence rising up to 33%. To investigate the frequency of IDH1/2 mutations in pediatric AML, we characterized the mutational hotspot (exon 4) of these genes in diagnostic samples from 460 pediatric AML patients. Our analysis identified somatic IDH1/2 mutations in 4% of cases (IDH1 R132 n= 8; IDH2 R140 n= 10) and the minor allele of single-nucleotide polymorphism (SNP) rs11554137 in 47 children (10.2%). IDH mutations were associated with an intermediate age (P= 0.008), FAB M1/M2 (P= 0.013) and nucleophosmin1 mutations (P= 0.001). In univariate analysis, IDH mutated compared with IDH wildtype patients showed a significantly improved overall survival (OS; P= 0.032) but not event-free survival (EFS; P= 0.14). However, multivariate analysis did not show independent prognostic significance. Children with at least one minor allele of IDH1 SNP rs11554137 had similar EFS (P= 0.27) and OS (P= 0.62) compared with major allele patients. Gene expression profiles of 12 IDH mutated were compared with 201 IDH wildtype patients to identify differentially expressed genes and pathways. Although only a small number of discriminating genes were identified, analysis revealed a deregulated tryptophan metabolism, and a significant downregulation of KYNU expression in IDH mutated cases.