Following seizure control with antiepileptic drugs and normalization of electroencephalogram, behavioral problem may appear for the first time in an epileptic patient. This phenomenon has been termed 'alternative psychosis'. However, it remains poorly understood in absence of any definite diagnostic criteria, and there are no specific guidelines to treat the condition. Here we report a case of an untreated patient of epilepsy of 13 years duration, who had onset of first episode non-specific aggressive behavior within 1 week after starting treatment with sodium valproate, which responded adequately to a short course of low dose risperidone. We conclude that alternative psychosis may have a variable clinical presentation and may respond favorably to antipsychotic drugs.