This study evaluated the relationship between sedative-like subjective responses to ethanol and triazolam in normal, healthy volunteers. It was hypothesized that subjects' responses to the two drugs would be correlated, because of the common mechanism of action of the drugs at the GABAA receptor complex. Twenty-seven volunteers (14 male, 13 female), aged 21–35 years, received beverages or capsules containing ethanol (0.2, 0.4 or 0.8g/kg), triazolam (0.125, 0.25 or 0.5 mg) or placebo (two sessions) on eight separate sessions in a random order. Various self-reported and objective drug effects were measured, including measures of sedative-like subjective effects, as indexed by the ARCI PCAG scale. PCAG scores of individual subjects across the three active doses of each drug were fitted with a straight line function (y = a + bx), and the correlation of the slopes from the fitted curves for ethanol and triazolam was examined. Among the participants who reported any sedative-like responses to ethanol, the sedative-like effects of ethanol and triazolam were positively correlated. That is, subjects who exhibited the steepest dose-related effects on measures of subjective sedation after ethanol also exhibited the steepest slopes after triazolam. These findings provide partial support for the idea that ethanol and triazolam produce their sedative-like effects through the same mechanism. © 1999 Lippincott Williams & Wilkins.