This paper reviews the available research on the predictors of parental engagement in preventive and therapeutic psychological interventions that target mental health problems in children. Based on previous literature, seven predictors concerning parental motivation to engage are considered: perceived child problems, perceived parenting, attributions of problems, self-efficacy, expectations about treatment, perceived obstacles and global motivation to engage. PRISMA guidelines for systematic review were used to conduct the literature search. Thirty-seven studies that examined prospective relations between parental cognitions evaluated at the beginning of the intervention and parental engagement during the intervention were included. Most studies focused on the parents’ perception of the child’s problems and of parenting, with fewer studies examining the role of the other parental cognitions. The results suggest that the psychological dimensions proposed in motivational models may play an important role in understanding parental engagement in preventive and therapeutic psychological interventions.