Previous research highlights how schools value white, middle-class modes of parental involvement, we know less about Latinx parents' involvement in their children's schools. This article compares the participatory patterns of Latinx and non-Latinx white parents whose children attend a Spanish/English dual-immersion school in Los Angeles. Drawing from 66 interviews and 20 months of participant observation, I find that all parents participate actively but are channeled into racially segregated Parent Teacher Organizations (PTO) based on the reputation, demographic composition and informal culture of each of these organizations. This organizational segregation disadvantages Latinxs -- working-class Latinx parent efforts garner less power and recognition and middle-class Latinx are less active in PTOs, as they feel they do not 'fit' in either organization. This article illustrates how school-based parental involvement is stratified in ways that are not fully captured by solely focusing on participation, and demonstrates how parent organizations can function as racialized organizations that perpetuate inequality.