Concentrations of dehydroepiandrosterone sulfate (DHAS) in saliva and serum were determined in 11 healthy men aged 23-40 yrs, 55 healthy, non-medicated women aged 20-81 yrs and 13 healthy women aged 20-30 yrs, all taking combined oral contraceptives (OC). Serum DHAS was higher in men than in women of corresponding age and was negatively correlated to age in OC-free women. These sex- and age-related differences were not found for salivary DHAS. Salivary and serum DHAS values were poorly correlated and the ratios between salivary and serum DHAS were variable, with a tendency to higher values in older subjects. Low saliva/serum DHAS ratios were found in OC users. The lack of a uniform, unequivocal relation between DHAS concentrations in saliva and serum renders salivary DHAS assays unsuitable for clinical purposes.