Student engagement and motivation have historically been studied within two different research literatures with little convergence. Recently, scholars have begun to integrate these two constructs with the examination of various school-related outcomes such as dropout, delinquency, and academic achievement. Few studies have examined social-emotional/behavioral functioning as the outcome. This study examined the relations between student engagement, motivation, and social-emotional and behavioral functioning in a sample of sixth-grade students. Specifically, a model in which engagement mediates the relation between motivation and social-emotional/behavioral functioning was tested. This hypothesized model was not supported; rather an alternative model emerged in which motivation is the mediator in the relation between engagement and social-emotional/behavioral functioning. A closer examination of each of the indicators of engagement and motivation revealed that certain indicators of engagement and motivation tended to align with each other. Interpretation of results and implications for practice are discussed.