Clathrin-coated vesicles (CCVs) are ubiquitous in eukaryotes. In animal cells they selectively transport receptor-ligand complexes from their sites of formation (plasma membrane and trans -Golgi network) to a low pH sorting compartment (the endosome) where the complex dissociates. Recognition and targeting of endocytotic and lysosomal cargoes occurs by the interaction between ‘adaptor' complexes and specific motifs on the cytoplasmic tails of receptors. The various coat polypeptides in plant CCVs suggest a highly conserved structure and function in all eukaryotes. As in mammalian cells, CCVs are formed at the trans -Golgi network in plants, and were originally considered to carry storage proteins and acid hydrolases. However, based on the recent discovery that some plant cells contain two types of vacuole, it now appears that smooth-surfaced ‘dense' vesicles are principally involved in the transport of storage proteins to storage vacuoles, and that CCVs might be involved in carrying acid hydrolases to lytic vacuoles. A potential receptor for vacuolar proteins has been isolated from pea cotyledon CCV fractions, although its interaction with adaptor polypeptides and the assembly of adaptors with clathrin remains to be established.