The present study examined the impact a 14-week sport stacking (cup stacking) exercise intervention would have on children's handwriting quality and speed. Eighty-three second graders were randomly assigned to either an experimental or a control group. The experimental group (n = 42) participated in a 15-min session of sport stacking activities every school day for 14 weeks, and the control group (n = 41) experienced other supervised physical activities using the same time interval and duration. The dependent variables, handwriting speed and accuracy, were measured pre- and postintervention. Results showed a significant test effect, F(1, 81) = 19.1, p = 0.001, with all students in both groups increasing handwriting speed posttest. Moreover, a marginal interaction between group and test emerged, F(1, 81) = 3.1, p = 0.08, suggesting a tendency that the experimental group had a greater improvement in writing speed than the control group. No difference was found in handwriting accuracy. The results were not conclusive, and further investigations are recommended to test the potential effect of sport stacking activities on enhancement of perceptual-motor function, specifically handwriting skill for school children.