Divalproex sodium is an anticonvulsant agent approved for use either alone or in combination with other antiepileptic drugs for simple and complex absence seizures and mania. Four double-blind placebo-controlled studies have confirmed that divalproex sodium/valproate is an effective migraine treatment. In all of the clinical studies, whether open, retrospective, or placebo-controlled and double-blind, valproate was an effective preventive treatment for migraine. There was a reduction in the number of migraine attacks, and migraine duration and intensity were also reduced in some instances. It is equally as effective in patients with severe frequent migraines as in those with less severe migraines. In clinical trials, the most frequent adverse events reported by patients treated with divalproex sodium were nausea, asthenia, dyspepsia, dizziness, somnolence, and diarrhea, with most adverse events being mild to moderate in severity.