This opinion article discusses the role that dopamine plays in motivating gambling behavior. It is commonly believed that monetary gain is the cause of gambling behavior in humans. Mesolimbic dopamine (DA), the chief neuromediator of incentive motivation, is indeed released to a larger extent in pathological gamblers than in healthy controls during gambling episodes as in other forms of compulsive and addictive behavior. However, recent findings indicate that the interaction between DA and reward is not so straightforward. This opinion article discusses the role of DA in motivating gambling behavior.