beta-Phenylethylamine is an endogenous brain amine which has been characterised as an endogenous amphetamine. The rewarding properties of the structurally similar drug amphetamine in humans and other species indicate a possible role for endogenous beta-phenylethylamine in neural processes underlying reward or reinforcement. Evidence for reinforcing properties of beta-phenylethylamine in the drug self-administration and place preference paradigms is briefly reviewed. The possibility that endogenous beta-phenylethylamine may be involved in reinforcement processes is also considered in relation to studies of intracranial self-stimulation. The contrasting aversive stimulus properties of beta-phenylethylamine and of amphetamine are described.