Dehydroepiandrosterone sulfate (DHAS) was measured in serum from 274 children and adolescents aged 1 month to 18.7 years, and in 38 healthy adults. In the pediatric group, which comprised 131 males and 143 females, serum DHAS was markedly age-dependent. Values declined between 1 and 5 months after birth, but were generally less than 4 mumol/L. Between 6 months and 7 years DHAS was less than 0.5 mumol/L in boys and less than 1.0 mumol/L in girls. Above 8 years DHAS progressively increased in both sexes to less than 13 mumol/L in mid-late teenage males and less than 12 mumol/L in females of the same age, similar to the values observed in the adults. In children and adolescents over 10 years, there was considerable overlap in DHAS values between groups of children classified by pubertal stage, resulting from the dissociation between adrenal and gonadal development during normal puberty.