Diplopia is a condition that involves seeing double and impairs quality of life. Acute diplopia can be seen with some general medical drugs and psychotropic drugs. Aripiprazole is a new atypical antipsychotic agent; it has partial agonist activity at D2 and 5-HT1A receptors and antagonist activity at 5-HT2A receptors. This paper reports development of diplopia, a rare adverse effect of psychotropic drugs, in a 24 year old patient with schizophreniform disorder following use of oral aripiprazole. Clinicians should keep in mind that diplopia may occur with aripiprazole treatment.