Psychostimulant (cocaine, amphetamine and its derivatives) addiction is an important health problem with implications in social and economic life. Although mesocorticolimbic dopamine system plays a crucial role in the mechanism responsible for the rewarding effects of these drugs, recent data also show involvement of the brain serotonin (5-HT) system. In the present review we discuss the role of 5-HTIB receptors in the psychostimulant addiction on the base of the effects of 5-HTIB receptor ligands on the behavioral effects of the psychostimulants in experimental models (sensitization, intracranial self-stimulation, conditioned place preference, self-administration and extinction/reinstatement model) used to assess their addictive properties. Moreover, the effect of long-term treatment with psychostimulants on 5-HTIB receptors is also discussed.