Alcoholism is transmitted in families. The complexity and heterogeneity of this disorder has made it difficult to identify specific genetic correlates. One design with the potential to do so is the family-based association study, in which the frequencies of genetic polymorphisms are compared between affected and nonaffected members. Reduced central serotonin neurotransmission is associated with features of an antisocial subtype of alcoholism, although a primary deficit has not been traced to a particular component. Genetic markers related to the sertonergic system have been identified, located, and cloned. If associations can be discovered, the development process for pharmacotherapy could be facilitated. In this review, the evidence for the involvement of the serotonergic system in antisocial alcoholism is examined, and the potential for family-based association studies to identify specific components that may be involved is discussed.