In a double-blind cross over randomized study for the first two nights efficacy and safety of triazolam 0.25 mg and loprazolam 1 mg have been compared in 67 out-patients complaining of common insomnia and treated by general practitioners. After the second night patients had to choose one of the two treatments and were continuing a 3-week treatment period with the preferred one. In case of no preference they received one of the 2 drugs according to a new randomization. Cross over administration of the two drugs for the first two nights shows that with triazolam global help to get in sleep is greater (p = 0.016) and sleep latency is shorter (p = 0.07) than with loprazolam, and number of night awakenings is decreased (p = 0.02) compared to loprazolam. Patients felt more rested under triazolam (p = 0.015) than loprazolam. Triazolam (N = 31) is more frequently preferred than loprazolam (N = 19) p = 0.09. Preferred treatment continued to be effective during the following three weeks and quality of sleep improved drastically for all items compared to baseline data (p = 0.01). Both treatments are well tolerated (4 drop-outs for side-effects: 2 under each treatment). The one-week tapering period allows progressive withdrawal with rare reappearance of minimum sleep disorders (5 cases: 2 under triazolam, 3 under loprazolam).