A double-blind, parallel group, randomized trial was carried out to compare the hypnotic efficacy of 1.0 mg loprazolam and 5.0 mg nitrazepam in 40 elderly patients. All had disturbed sleep patterns, which were not the result of physical illness, and had been shown to be placebo non-responders during a 3-day placebo screening period. Patients received active medication for 7 nights. Both loprazolam and nitrazepam significantly improved sleep patterns, as measured by patient self-rating scales and night nurses' global assessments, in comparison with the placebo baseline screen (p less than 0.001). No significant differences in efficacy were shown between drug treatments and no untoward effects were recorded which could be attributed to either drug. The results suggest that 1.0 mg loprazolam is an effective and well-tolerated hypnotic in elderly patients suffering from insomnia.