This study examined the effects of plyometric-based structured game active breaks on fundamental movement skills (FMS), muscular fitness, student self-perception, and teacher’s rating of actual behaviour in Grade 3 and 4 students. Primary school children aged 8–10 years old, from four classes, were cluster-randomly assigned to an intervention group (IG) (n = 54) or a control group (CG) (n = 48). The IG participated in structured plyometric-based game active breaks for 7–10 minutes daily, for six consecutive weeks. The CG resumed their regular daily school routine. FMS were assessed with the Canadian Agility Movement Skills Assessment test, and muscular fitness with the standing long jump (SLJ), countermovement jump (CMJ), and seated medicine ball chest throw tests. The Self-Perception Profile for Children and the Teacher’s Rating Scale of Child’s Actual Behaviour assessed student self-perception and teacher’s perception of student actual behaviour, respectively. A significant (p < 0.01) interaction group by time was observed, with greater improvements in the IG compared to the CG in FMS (%diff = 13.11, ƞp² = 0.12), SLJ (%diff = 6.67, ƞp² = 0.16), seated medicine ball chest throw (%diff = 4.69, ƞp² = 0.08), student social self-perception (%diff = 9.31, ƞp² = 0.10), student scholastic selfperception (%diff = 7.27, ƞp² = 0.10), and teacher perception of student social competence (%diff = 8.31, ƞp² = 0.05). No difference (p > 0.05) was found in other variables. Integrating plyometric-based structured game active breaks into primary school settings evidenced improvement in FMS, muscular fitness, student selfperception, and teacher’s rating of student actual behaviour.