The aim of this paper was to review the state of the art in personality traits and personality disorders in pathological gambling. As regards personality traits, the results of specific profiles of pathological gamblers (in terms of neuroticism, extroversion, psychoticism, sensation seeking, etc.) are not conclusive. The personality trait that obtains most support by empirical evidence is impulsivity. Pathological gamblers are more impulsive than the average population. In addition, there are few studies on personality disorders. There is a tendency for a higher proportion of gamblers to be found within the cluster B category (antisocial and borderline, mainly). Finally, implications of this kind of studies for future research and clinical practice are commented upon.