The current study validated the Math Homework Purpose Scale (MHPS) for preadolescents. Having randomly split participants into two subsamples, we conducted exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) on subsample 1 (n = 293) and subsample 2 (n = 292), respectively. Both EFA and CFA indicated that the MHPS consisted of three factors: Academic, Self-regulatory, and Approval-seeking Reasons. Given an adequate level of measurement invariance, we further examined the latent mean difference across gender. Results revealed no statistically significant mean differences in Academic, Self-regulatory, and Approval-seeking Reasons across gender. Finally, consistent with theoretical expectations, Academic and self-regulatory Reasons were positively correlated with homework effort, homework completion, and math achievement.