Detailed, within-subjects Golgi analyses of regional differences in cerebellar Purkinje cell dendritic development are impractical due to the capriciousness of that technique. Immunocytochemical labeling of microtubule-associated protein 2 (MAP2) was used to reveal the dendritic development of Purkinje cells, and indicated marked differences in the timing of initial outgrowth of Purkinje cell dendrites for different lobules in the developing rat cerebellar vermis. In particular, an early maturing region of Purkinje cell dendritic outgrowth (lobules I, II, IX and X and along the primary fissure), and a late maturing region (distal lobule VI, lobule VII and dorsal lobule VIII) were documented.