The benzodiazepines (pronounced [ˌben-zō-dī-ˈa-zə-ˌpēn] , or "benzos" for short) are a class of psychoactive drugs considered minor tranquilizers with varying hypnotic, sedative, anxiolytic, anticonvulsant, muscle relaxant and amnesic properties, which are mediated by slowing down the central nervous system. Benzodiazepines are useful in treating anxiety, insomnia, agitation, seizures, and muscle spasms, as well as alcohol withdrawal. They can also be used before certain medical procedures such as endoscopies or dental work where tension and anxiety are present, and prior to some unpleasant medical procedures in order to induce sedation and amnesia for the procedure. Another use is to counteract anxiety-related symptoms upon initial use of SSRIs and other antidepressants, or as an adjunctive treatment. Recreational stimulant users often use benzodiazepines as a means of "coming down" (see: Drug abuse).

The long-term use of benzodiazapines can cause physical dependence. The use of benzodiazepines should therefore commence only after medical consultation and benzodiazepines should be prescribed the smallest dosage possible to provide an acceptable level of symptom relief. Dependence varies with the benzodiazepine used and with the user, with some reporting alprazolam dependence in as little as three days.