Fathers make important and unique contributions to positive child development. In spite of these findings the research literature has lagged in the study of the role and impact of fathers on child development and in the development of effective approaches and interventions for fathers. Parameters for additional study include the inclusion of fathers in treatment outcome studies, the engagement of fathers within studies once included, the retention of fathers in interventions and studies once engaged, and the appropriate measurement of father-related outcomes. A systematic review of 64 studies indicated that there is evidence fathers have been included within multiple studies aimed at improving parenting, but that there are relatively fewer studies of other targeted outcomes such as co-parenting. A set of recommendations for future directions in the next generation of father-focused studies in the child and adolescent psychology literature is presented, with an emphasis on improving study of the parameters of inclusion, engagement, retention, and measurement of outcomes. [This paper was published in "Journal of Clinical Child and Adolescent Psychology" v47 p847-862 2018.]