Treating anxiety disorders or for the short-term relief of the symptoms of anxiety. It is also used to treat seizures, certain types of muscle spasms, and symptoms of alcohol withdrawal (eg, agitation, tremor, hallucinations). Diazepam is also used before surgery or other medical procedures to help reduce anxiety and tension. It may also be used for other conditions as determined by your doctor. Diazepam is a benzodiazepine. It works by increasing the action of a certain chemical (gamma-aminobutyric acid [GABA]) in the brain and nervous system. This helps to reduce anxiety. It also helps to reduce seizure activity in the brain and to reduce muscle spasms.