This exploratory descriptive study looks at the characteristics of immigrant children in the greater metropolitan Los Angeles area who participate in organizations associated with their parents' country of origin. By drawing on the 2004 Immigration and Intergenerational Mobility in Metropolitan Los Angeles (IIMMLA) survey dataset, I bring together aspects of the participation and assimilation literatures in order to better understand who participates in ethnic organizations. Results provide evidence that ethnic organization participants differ from the full sample and from respondents who participate in community organizations; they exhibit more ethnic resource characteristics. Significant determinants of participation in ethnic organizations include having a larger numbers of close relatives in the Los Angeles metropolitan area, literacy in their parents' native language, higher education levels, and being married. These findings indicate that ethnic resources are more important to immigrant children who participate in ethnic organizations than attaining dominant characteristics or straight-line assimilation in society.