Protein phosphatase isoforms, PP1γ1, PP1δ, PP1α and PP2A (α and/or β), were immunohistochemically localized in the rat cerebellum. Purkinje cell perikarya, dendrites and spines were very PP1γ1 immunoreactive. PP1δ and PP1α were perinuclear in all neurons, PP1α also revealed a new cell type and PP2A was homogeneous in Purkinje cell soma and large dendrites. PP1γ1 seems to be dominant for dephosphorylation at the dendritic synapses of Purkinje cells. © 1995.