The major neutral urinary steroids have been quantitated by capillary gas chromatography and the reproducibility and accuracy of the method have been fully evaluated. Typical intra- and inter-assay coefficients of variation for individual steroids ranged from 4.9 to 10.1% and from 15.6 to 21.5%, respectively. Comparison of steroid values with alternate and commonly employed procedures for measuring urinary 17-oxosteroids, total 17-oxogenic steroids, and cortisol and plasma dehydroepiandrosterone-sulphate yielded correlation coefficients between 0.71 and 0.79. A definite relationship between serum cortisol and urinary trihydroxy-pregnanedione was also shown. Urinary androstenedione metabolites, however, could not be significantly (P greater than 0.05) correlated with the normalised androgen ratio in plasma.