This review summarizes research concerning the relation between paternal factors and child and adolescent psychopathology. When compared with mothers, fathers continue to be dramatically underrepresented in developmental research on psychopathology. However, findings from studies of children of clinically referred fathers and nonreferred samples of children and their fathers indicate that there is substantial association between paternal characteristics and child and adolescent psychopathology. Findings from studies of fathers of clinically referred children are stronger for fathers' effects on children's externalizing than internalizing problems. In most cases the degree of risk associated with paternal psychopathology is comparable to that associated with maternal psychopathology. Evidence indicates that the presence of paternal psychopathology is a sufficient but not necessary condition for child or adolescent psychopathology.