The nucleus accumbens is gaining interest as a target for deep brain stimulation in refractory neuropsychiatric disorders with impulsivity as core symptom. The nucleus accumbens is composed of two subterritories, core and shell, which have different anatomical connections. Here, we tested the hypothesis that stimulation of the nucleus accumbens core and shell would have different effects on impulsivity. Rats received bilateral stimulation at the level of the nucleus accumbens core or shell during a reaction time task. Stimulation of the nucleus accumbens core significantly decreased impulsivity, while stimulation of the shell increased it. Our results support the hypothesis that the nucleus accumbens is a potential target to treat neuropsychiatric disorders related to impulsivity by deep brain stimulation. However, different behavioral effects resulting from stimulation of the subterritories should be taken into account.