The aim of the present investigation was to estimate the local effect of three plaque-inhibiting drugs on some glycosaminoglycans in rat skin. The drugs comprised chlorhexidine, dichlorhexidine, and trichlorhexidine; and the glycosaminoglycans examined were hyaluronic acid, chondroitin sulfate, and heparin. Glycosaminoglycans were measured by the carbazole method. Upon subcutaneous injections in rats, chlorhexidine, dichlorhexidine, and trichlorhexidine caused marked reductions in the surrounding skin's content of total hexosamine as well as of the three types of glycosaminoglycans. No significant difference could be demonstrated between the different types of glycosaminoglycans in this respect.