Radial glial cells are stem cells that play an important role in neuronal migration and proliferation in the developing brain. However, how radial glial cells contribute to the lamination of the cerebellar cortex is not well understood. We therefore used immunohistochemistry and BrdU labeling to follow radial glial cell differentiation, cell migration and cerebellar cortex development in mice from embryonic day 8 to postnatal day 180. We report that radial glial cells represent the stem cell population of the neuroepithelium of the neural tube, and act as progenitors for both neurons and neuroglia. In addition, radial glial cells not only give rise to the principal cells of the cerebellar cortex, the Purkinje and granule cells, but they also provide a scaffold for the migration of these cells. We conclude that radial glial cells play a pivotal role in establishing the laminar structure of the cerebellar cortex.