Increased parent school involvement is associated with better academic outcomes; yet, proximal contributors to this effect remain understudied. We focus on one potential proximal contributor, youth's positive and negative future self-images or "possible selves," reasoning that if parent school involvement fosters possible selves, then interventions aimed at enhancing youths' possible selves should moderate the negative effect of low parent school involvement. We examine a 2-year follow-up of a randomized clinical trial of a possible self-based intervention (N=239), demonstrating with regression equations that the intervention moderated the association of low parent school involvement with worse grades and less school-engaged behavior. Low parent school involvement negatively influenced achievement among control, not intervention youth, suggesting that school-based, possible self-focused interventions can moderate the undermining effect of low parent school involvement.