This study examined the effects of Reading Recovery on children's motivational levels, and how motivation may contribute to the effect of the intervention on literacy achievement. Prior studies concluded that Reading Recovery was positively associated with increased student motivation levels, but most of those studies were limited methodologically. The achievement and motivation levels before and after the intervention of Reading Recovery students and similarly low-performing first-grade students were compared using structural equation modeling. It was found that Reading Recovery had a 0.31 treatment effect on achievement after controlling for baseline achievement and motivational differences among the treatment and comparison students. Reading Recovery also was associated with greater average levels of posttest motivation, and motivation was found to mediate the treatment-achievement relationship. This study highlights how important it is for early reading interventions to consider the role motivation plays in literacy acquisition.