In a double-blind crossover study involving 15 insomniac subjects, the hypnotic efficacy of lorazepam, 2 and 4 mg, was compared with flurazepam, 15 and 30 mg, and placebo. Five subjective measures were used: onset, length, and depth of sleep, number of times awakened, and satisfaction with the hypnotic. Lorazepam in 2- and 4-mg doses was comparable in hypnotic efficacy to flurazepam, 30 mg, according to most parameters of measurement. Side effects were minor, although relatively numerous at the 4-mg doses.