Using polysomnography, sleep effect was studied, then the sleep latency test (SLT), Stanford Sleepiness Scale (SSS), and Kwansei Gakuin Sleepiness Scale (KSS) were studied the next morning after administration of either an inactive placebo (PL), 0.125 mg triazolam (TL), 0.25 mg triazolam (TH), or 0.25 mg brotizolam (BR). Ten healthy male volunteers were used for the double-blind crossover design. TL increased the percentage of stage 2 sleep significantly compared with PL, whereas TH decreased the number of stage shifts significantly. TH and BR increased the percentage of stage 2 sleep significantly and decreased the percentage of rapid eye movement sleep significantly. Although no drug had any effect on SSS and KSS, BR decreased the sleep latency in SLT significantly.