This paper briefly reviews the clinical presentation of pathological gambling and presents data related to the co-occurrence of pathological gambling and substance use disorders. Both epidemiological and treatment data are reviewed. The putative physiological substrates underlying pathological gambling are described, along with the limited genetics data. Types of treatments applied to gamblers are described, including data on efficacy and overlap of issues that relate to both gambling and substance use disorders. Finally, areas for future research are suggested to advance our understanding of pathological gambling and its relationship to substance use disorders.