In acute illness, cortisol secretion increases whereas that of the adrenal androgens, dehydroepiandrosterone and dehydroepiandrosterone sulfate declines. The present study examined if a similar dissociation of cortisol and adrenal androgen secretion occurs in poorly controlled diabetes mellitus. Serum concentrations of cortisol, dehydroepiandrosterone and dehydroepiandrosterone sulfate obtained at 08.00 were compared in 13 post-pubertal diabetics (mean age 18.0 years) in good control (HbA1C<8.0%) and 10 post-pubertal diabetics (mean age 17.0 years) in poor control (HbA1C> 10.0%). Those in poor control had significantly higher serum cortisol (597±94 nmol/l vs 479±208, p < 0.05), lower dehydroepiandrosterone (13.1±5.5 nmol/l vs 25.3±16.9, p<0.025) and lower dehydroepiandrosterone sulfate (4.5±2.4 μmol/l vs 7.0±3.7, p<0.025). The ratios of dehydroepiandrosterone and dehydroepiandrosterone sulfate to cortisol were also significantly lower in those with poor control. It is concluded that poor control of insulin-dependent diabetes mellitus results in a dissociation of cortisol and adrenal androgen secretion.