The antiepileptic properties of carbamazepine (Tegretol) and clonazepam (Rivotril) were compared in a double-blind randomized study comprising 36 patients with newly diagnosed, untreated psychomotor epilepsy (partial seizures with complex symptomatology). No significant differences were found between the two drugs during the 6 months of treatment. Measurements of concentrations in plasma confirmed that the patients exceeded the accepted lower limit for therapeutic range of the drugs.