Applying a three-level meta-analysis, the goal of our investigation was to examine the relationship between parental homework involvement and students' achievement, and to study whether certain study features could have resulted in the inconsistent results regarding this relationship across primary studies. We identified a total of 28 studies (32 independent samples) with 252 effect sizes for a total of 378, 222 participants. Our meta-analysis revealed an overall weak negative relationship between parental homework involvement and students' achievement (r = -0.064, p < 0.001). The overall relationship was moderated by dimension of parental homework involvement. Specifically, students' achievement was positively related to autonomy support, but largely unrelated to content support, parental control, frequency, and mixed.