The current multilevel meta-analyses and systematic review encompass 47 longitudinal studies of motivation and academic achievement in primary and secondary education. Our inclusion criteria extended beyond studies centred on self-belief type of motivation constructs, as we also selected studies using other motivation constructs (e.g. achievement goals). The findings offered mixed support for the reciprocity. The pooled effect of achievement on motivation was nearly twice as strong ([beta] = 0.176) as that of motivation on achievement ([beta] = 0.096). The effect of achievement on motivation held across different motivation constructs, albeit exhibiting more robust reciprocity for self-belief constructs ([beta] = 0.227) than for other constructs ([beta] = 0.091). The effect of motivation on achievement was exclusively found for self-belief ([beta] = 0.157) and not for non-self-belief motivation. Overall, the medium-to-high heterogeneity between studies and within studies suggests that pivotal factors in the motivation-achievement dynamics may not have been captured yet.