Isolation and caracterization of glycosaminoglycans were performed in uteri and salivary glands of castrated and normal female rats and in castrated female rats receiving daily doses of 1 or 10 μg of oestradiol benzoate. The uronic acid concentration in the uterus was increased by castration and decreased by the administration of oestradiol benzoate but due to the changes in uterine weight the uronic acid content of each uterus was decreased by castration and increased by oestradiol benzoate. Chromatographic separation of glycosaminoglycans was performed on cellulose microcolumns. The concentration of each glycosaminoglycan fraction was increased by castration and decreased by oestradiol benzoate. No changes in the uronic acid concentration or total glandular content or in the chromatographic distribution of the fractions were found in the parotid, submaxillary or retrolingual glands.