Topiramate is a chemically novel antiepileptic drug that is available in a number of countries for the treatment of partial seizures. Although the mechanism of action of this substance is not yet fully understood, preclinical evidence suggests that it interferes with sodium conductance, augments the effect of γ-aminobutyric acid, blocks glutamate receptors, and has weak carbonic anhydrase inhibiting properties (4). Topiramate has a favorable pharmacokinetic profile and is generally well tolerated in patients with epilepsy (5). Psychotropic side effects (such as abnormal thinking) can usually be controlled by slow escalation of the dose. Unlike most other psychopharmacological drugs, the substance is associated with substantial weight loss. Here we report the efficacy of topiramate in a patient with acute mania by using an on-off-on study design.