Over the last decade, understanding of glioma on a molecular level has greatly expanded. However, optimal incorporation of molecular markers into clinical care is controversial. We briefly review the potential utility of molecular stratification in refining histologic diagnosis, prognosis, and treatment decisions, focussing on 1p/19q co-deletion, MGMT promoter methylation, EGFR mutations, and IDH mutation. The most recently discovered IDH mutation is a striking example of a rapid implementation of a molecular marker for prognostication into common clinical use.