This study aimed to examine parental involvement in early childhood education in relation to coparenting relationships and motivational beliefs regarding parental involvement in education. In line with the aim of the study, an explanatory correlational research design was adopted. The data for the study was gathered from 1,618 heterosexual parents of preschoolers in Turkey through multiple data collection instruments: a demographic information form, the Coparenting Relationship Scale, the Role Activity Beliefs Scale, the Self-Efficacy Beliefs Scale, and the Family Involvement Questionnaire. To address the aim of the study, an initial and a final model were created and tested, to explore the direct and indirect relationships between the study variables. These models first explored whether coparenting predicted motivational beliefs and parental involvement and, second, investigated motivational beliefs as mediators of the relationships between the quality of coparenting and the levels of parental involvement in education. The results of the analysis indicated that coparenting support was directly and positively linked to role activity and self-efficacy beliefs; however, coparenting undermining was directly and negatively linked to self-efficacy beliefs, school-based involvement, and home-based involvement. Role activity and self-efficacy beliefs fully mediated the relationship between coparenting support and parental involvement. Moreover, self-efficacy partially mediated the relationship between coparenting undermining and parental involvement. In conclusion, the current study revealed that the qualified relationships between parents in their parenting, associated with their individual motivational beliefs, can enhance parental involvement in education.