Medulloblastoma, a cerebellar small blue cell malignancy, is a significant cause of morbidity and mortality in pediatric oncology. Current clinical prognostication and stratification methods include clinical factors and histological subgrouping. Transcriptional profiling studies have identified multiple distinct molecular subgroups of medulloblastoma, differing in demographics, transcriptomes, somatic genetic events, and clinical outcomes. A consensus conference in Boston in 2010 led to the agreement on four main subgroups: Wnt, Shh, Group 3, and Group 4. Each subgroup has unique demographic, transcriptional, genetic, and clinical characteristics. The Wnt subgroup is associated with excellent long-term survival, while the Shh subgroup is linked to Sonic Hedgehog signaling pathways and has a dichotomous age distribution. Group 3 tumors are mostly 'classic' medulloblastomas with high rates of metastasis and poor prognosis. Group 4 tumors, characterized by isochromosome 17q, have intermediate prognosis. The molecular classification of medulloblastoma will continue to evolve, and it is crucial for identifying target cohorts for therapy and improving outcome prediction.Medulloblastoma, a cerebellar small blue cell malignancy, is a significant cause of morbidity and mortality in pediatric oncology. Current clinical prognostication and stratification methods include clinical factors and histological subgrouping. Transcriptional profiling studies have identified multiple distinct molecular subgroups of medulloblastoma, differing in demographics, transcriptomes, somatic genetic events, and clinical outcomes. A consensus conference in Boston in 2010 led to the agreement on four main subgroups: Wnt, Shh, Group 3, and Group 4. Each subgroup has unique demographic, transcriptional, genetic, and clinical characteristics. The Wnt subgroup is associated with excellent long-term survival, while the Shh subgroup is linked to Sonic Hedgehog signaling pathways and has a dichotomous age distribution. Group 3 tumors are mostly 'classic' medulloblastomas with high rates of metastasis and poor prognosis. Group 4 tumors, characterized by isochromosome 17q, have intermediate prognosis. The molecular classification of medulloblastoma will continue to evolve, and it is crucial for identifying target cohorts for therapy and improving outcome prediction.