It is well established that children of problem drinkers have an increased risk of developing mental health problems, including drinking and drug misuse problems, depression, eating disorders, conduct disorders, and delinquency. However, compared to the hundreds of studies that have examined the effects of parental problem drinking on their children, the genetics of problem drinking, and the physical and mental problems of these children, it is disappointing that so few studies have explored the possibilities of prevention. Despite all the research on children of problem drinkers, we have no usable operationalizations of what problem drinking is, or when a child can be defined as a child of a problem drinker. Furthermore, no valid screening or severity assessment instruments are available; there is no solution for the ethical dilemma of the need to involve parents while these parents are at the same time the problem; very few theory-driven prevention programmes have been developed; very little is known about protective factors that could be the focus of prevention programmes; and we have no programmes that can be considered to be 'evidence based. This paper describes these problems, presents an overview of the prevention research in this area, and gives some directions for future research.