Although the intermediates for sulfation of proteochondroitin and proteodermatan have been known for several decades, organizational aspects of this formation have not been clearly defined. Work in several laboratories, including our own, have indicated a pattern which strongly suggests that sulfation ordinarily takes place together with glycosaminoglycan polymerization in the same Golgi sites, and with close relationship to aspects of polymer elongation, polymer modification and polymer termination. The organization of sulfation together with polymerization may be a major factor controlling the location, type, and degree of sulfation, which in turn may direct specific functions of these proteoglycans.