The landscape of gambling has dramatically changed. In addition to more and more jurisdictions having casinos, electronic gambling machines, lotteries and sports wagering in close proximity to individuals, online gambling has dramatically increased. Gambling has moved from being a negatively perceived activity associated with sin and vice to its current state of being viewed as a socially acceptable recreational pastime. Upwards of 80 percent of individuals report having gambled for money during their lifetime, and governments throughout the world have come to recognize that regulated forms of gambling can be a significant source of revenue. While the vast majority of individuals have no gambling-related issues, an identifiable proportion of both adults and adolescents experience significant gambling-related problems. In spite of the growing body of research which has identified many of the risk and protective factors associated with excessive problematic gambling, a limited number of prevention and treatment programs exist. This chapter examines current knowledge concerning the efficacy of existing harm minimization prevention programs and treatment of gambling disorders.