Valproate is a major antiepileptic drug that is now in worldwide clinical use. Nevertheless, the mechanism of action of valproate remains obscure. A number of recent articles have discussed this subject, and we ourselves have participated in a detailed review of the known actions of valproate (Chapman et al., 1982a). The object of this article is to present the most recent advances in our knowledge of valproate's actions, in particular, the pharmacological effects of some analogues and metabolites, the newest findings concerning the γ‐aminobutyric acid (GABA) hypothesis, and the possible involvement of valproate with ionic processes related to the intrinsic mechanisms of epilepsy at the cellular lev