Parent participation in school management has been promoted as a strategy for holding schools accountable for education quality and outcomes. However, the evidence has proven inconclusive and limited in explaining mechanisms to affect student achievement. By using public school student data derived from the Programme for International Student Assessment 2015, this study examines how 1) participation of a student's own parents in school management, which would affect their learning support at home and 2) participation of a group of parents, which would influence school decisions and thus affect the learning environment at school, are associated with student achievement in Croatia, Georgia, Portugal, the Dominican Republic, Mexico, Korea, Hong Kong, and Macao. I found no evidence that parent participation in school management contributed to improving student achievement. Instead, depending on the country, a negative association is derived from either individual-level or school-level parent participation. The associations are not moderated by parents' socioeconomic status but by school's openness to parental engagement in some of the countries, indicating that what matters might not be participation per se but the degree of engagement. The findings underscore the importance of understanding mechanisms and conditions in which parent participation affects student learning in context to design effective participatory school governance.