Research on familial factors in illicit drug abuse has been approached from the perspectives of psychiatric epidemiology, which aims to assess familial clustering of disorders, and clinical psychiatry, which focuses on intrafamilial dynamics. To date, however, these two research traditions have existed in relative isolation from each other, and there has been little consideration given to enhancing the understanding of familial factors in drug abuse by combining these approaches. The intention of this article is to critically review the literature in these two areas and to offer suggestions as to how the strengths from each could be applied in a comprehensive research approach.