1. From an earlier cross-sectional survey of 343 public servants, 15 pairs of non-smoking teetotallers and heavy drinkers (alcohol intake more than 350 mL/week) were matched for age and adiposity and utilized for a case-control study of the effects of alcohol on 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) activity and blood pressure. 2. Two successive 24 h urine collections were analysed by radio-immunoassay (RIA) for cortisol excretion, and for the cortisol and cortisone metabolites, tetrahydrocortisol (THC), allo-tetrahydrocortisol (allo-THC) and tetrahydrocortisone (THE), by capillary column gas chromatography. 3. Heavy drinkers had higher systolic and diastolic blood pressure (BP) than teetotallers (132.6 +/- 2.5 vs 123.2 +/- 1.3 and 78.7 +/- 1.6 vs 71.7 +/- 1.4, respectively; unpaired t-test, P less than 0.01). Twenty-four-hour urinary sodium and cortisol excretion were similar in the two groups. 4. The THC plus allo-THC:THE ratio was similar in drinkers and teetotallers (1.81 +/- 0.20 vs 2.03 +/- 0.20), consistent with no effect of alcohol on 11 beta-OHSD activity. The ratio of THC to allo-THC was increased in drinkers compared with teetotallers (1.49 +/- 0.18 vs 1.05 +/- 0.13; unpaired t-test, P less than 0.05), consistent with either a decrease in 5 alpha-reductase activity or an increase in 5 beta-reductase activity. 5. This study provides no evidence for alcohol-related inhibition of 11 beta-OHSD, despite substantially higher blood pressures in heavy drinkers compared to teetotallers. Such an effect is, therefore, unlikely to contribute significantly to the mechanism of alcohol-related hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)