The efficacy of sodium valproate (Depalept) versus placebo in the treatment of migraine was evaluated in a double-blind randomized cross-over study in twenty-nine patients. The patients were divided into two groups each of which was alternately given 400 mg of sodium valproate B.I.d or placebo for eight weeks and then crossed over for an additional eight weeks. Our results show that in 86.2% of the patients sodium valproate was effective in preventing migraine or reducing the frequency, severity and duration of the attacks. In general, the drug was well tolerated and proved to be an effective treatment in migraine.