Parental involvement within schools has proven to be an effective mechanism for student achievement; however, full involvement of parents in schools is yet to be attained. This literature review investigates which parents are left behind within schools and offers conclusions as to why this might be. The types of parental involvement that occur within schools are considered. This is followed by an examination of the effects of parents’ socioeconomic status for educational involvement and the involvement of minority parents. Family dynamics and how familial relationships affect parental involvement are also explored. Finally, strategies to achieve universal parental involvement are proposed. Overall, the literature review reveals that, while some parents are left behind more often than others, it is ultimately up to the efforts of the school to engage all parents equally in their child’s education.