Low-grade gliomas (LGG) are the slowest growing type of brain cancer that often affects young adults. Of all LGG cases, older patients were associated with the poor prognosis compared to younger patients. However, the molecular mechanism underlying this association remains unclear. Here, we compared genes expression profiles between younger (age≤50) and older (age > 50) patients from The Cancer Genome Atlas (TCGA) and demonstrate the age-related gene expressions. Pathway and gene set enrichment analysis reveal that differentially expressed genes (DEGs) between tumors of older and younger patients have been involved in cancer-related biological procedures, such as, transcriptional misregulation in cancer, nucleotide synthesis, mTOR, and DNA damage repair signaling. We also demonstrated that older patients have higher expression of Mitosis Kinase Score (MKS) and Tumor Inflammation Signature (TIS) which reflects high cell proliferation and high immune cell activity; respectively. The comprehensive characterization of gene-expression profiles in younger versus older LGG may explain the age-related prognosis and facilitate the development of potential therapeutic biomarkers for LGG.