Serum concentrations of iodothyronines, cortisol, prolactin, testosterone and the respective tropic hormones were measured in 32 noncirrhotic male alcoholics, aged 28-51 years, at the end of a long drinking period and subsequently during ethanol withdrawal over 1-2 weeks. Seven men had testicular atrophy. On admission one patient had high values for serum thyroxine (T4) and free thyroxine index (FT4I). A blunted response of serum thyrotropin (TSH) to thyrotropin-releasing hormone (TRH) was found in 9 men. Apart from a blunted TSH-response in one man the abnormalities disappeared during the first week of alcohol abstinence. Simultaneously the mean levels of serum T4, FT4I, triiodothyronine, free triiodothyronine index and reverse triiodothyronine were reduced by 12, 14, 5, 8 and 21%, respectively, and the mean of the maximum TSH-response to TRH was increased by 55%. At the time of stopping drinking two men had high morning values and six an abnormal diurnal rhythm of serum cortisol. High serum ACTH-levels associated with normal serum cortisol concentrations were found in 12 men. During the first week of alcohol abstinence the mean morning values for serum cortisol and ACTH were reduced by 18 and 42%, respectively. The serum ACTH-levels remained high in 6 men but the abnormalities in cortisol secretion disappeared. On admission four men had low serum concentrations of testosterone which were normalized during ethanol withdrawal over one week. At the same time the mean level of serum testosterone was increased by 19%. Mild hyperprolactinaemia found in 7 patients on admission disappeared in 4 men during the first week of ethanol withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)