peer reviewed ; Benzodiazepines currently represent the most widely prescribed family of hypnotic drugs. They possess obvious advantages: actual hypnotic efficacy, at least with short-term use, low toxicity, and excellent tolerance. However, several side effects need to be mentioned: besides morning drowsiness (which represents the untoward continuation of their sedative properties), anterograde amnesia, increase of daytime anxiety, and rebound insomnia. Moreover, benzodiazepines significantly modify several sleep parameters: they decrease slow wave sleep and delay the first period of REM sleep. Any hypnotic benzodiazepine should only be prescribed in case of actual need and after exclusion of non-pharmacologic means. The 'softest' agent, at the lowest dose, and during the shortest period should always be preferred.