Cerebella from suckling and adult rats were examined histochemically with 19 different biotinlabeled lectins. Purkinje cells from postnatal rats had a marked ability to combine with many lectins, but minimal ability was found in adult rats except for Con-A, LEL, and MAL lectins. The cell body of Purkinje cells on postnatal day 7 was strongly labeled with 6 lectins (Con-A, LTL, MAL, SJA, UEA-I, and VVA). Only moderate staining was observed with these lectins on postnatal day 5. The dendritic tree of the cells showed a moderate labeling ability with LTL and UEA-I on postnatal days 15 and 20. The dendritic tree was strongly labeled with MAL on postnatal days 10, 15, 20 and adult. Positive reactions were observed in the cells when cerebellar sections from rats on postnatal day 7 were incubated with 3 other lectins (AAL, LEL, and SBA). The cells on postnatal day 7 were rarely labeled with BSL-II, DBA, DSL, LCA, PNA, PSA, RCA120, SSA, STL, and WGA. Purkinje cells on postnatal day 7 may be rich in N-linked oligosaccharides, with terminal sugar structures that resemble blood-group-related antigens (type H) and/or tumor-related antigens. These glycoconjugates may be present at low levels in the Purkinje cells of adult rats. Dendrites of Purkinje cells of adult rats were strongly labeled by Con-A, LEL, and MAL. The dendrites of Purkinje cells may be rich in highly branched oligosaccharides.