Aripiprazole is a third generation atypical antipsychotic with pharmacological properties of a dopamine D₂ receptor partial agonist. In this presentation, we investigated whether a single administration of mice with aripiprazole affected stereotypy induced by methamphetamine (METH). Pretreatment of ICR mice with a single injection of aripiprazole (1 and 10 mg/kg, i.p.) attenuated the total incidence of stereotypical behavior induced by METH (10 mg/kg, i.p.) in an aripiprazole dose-dependent manner. Aripiprazole pretreatment alone had no effects on spontaneous locomotion. The stereotypy induced by METH alone was characterized by stereotypical biting, while the stereotypy induced by METH in combination with the dose of 1 mg/kg aripiprazole was predominantly characterized by stereotypical sniffing. No stereotypical behavior was observed when mice were treated with METH in combination with 10 mg/kg aripiprazole. Pretreatment of mice with 1 mg/kg aripiprazole produced an increase in the locomotor activity in mice treated with METH, but an attenuation of locomotion when mice treated with METH were pretreated with 10 mg/kg aripiprazole. These data suggest that the antagonism of METH effects by aripiprazole should be investigated as a potential treatment for METH addiction or METH overdose.