A double-blind crossover trial was conducted in 42 outpatients of either sex in order to obtain information on the properties of 7.5 mg of zopiclone in a general practice setting compared with 2 mg of flunitrazepam. Each patient went through two periods of treatment, each period lasting 10 days. A comparison of the effect of the drugs showed a significant difference with regard to effectiveness and sleep latency favoring flunitrazepam. When patient’s preferences were analyzed there was a highly significant difference favoring flunitrazepam both for effectiveness and tolerance. The side effects from both drugs were generally mild.