Aripiprazole is an atypical antipsychotic agent which has partial agonistic effect on dopamine D2 and D3 receptor. It is effective in the treatment of schizophrenia and bipolar disorder. Due to its partial agonistic effect, hyperactivity of dopamine may occur in the mesolimbic pathway. In the literature, there are few case reports about pathological gambling due to aripiprazole. In this article two case reports with a tendency to gambling and alcohol abuse under treatment of aripiprazole who show pathological gambling behaviour are reported. Cases have a history of gambling in the past. Due to the use of aripiprazole, pathological gambling behaviour occurs quickly and with discontinuation of aripiprazole it ended completely. In spite of its very low therapeutic drug monitorization (TDM) level, aripiprazole may cause this. Aripiprazole causes pathological gambling by forming hyperdopaminergic condition in the mesolimbic dopaminergic pathway. Aripiprazole should be recommended carefully to the patients who are impulsive and have a history of alcohol/substance abuse.