The EU is pursuing an increasingly explicit agenda in relation to young immigrants and asylum-seekers, leading the supra-national legislature to grapple with the question of how to ensure that children's rights are upheld through this body of law. The tool of mainstreaming, which ensures that a particular concern is promoted through its incorporation into the entire law-making process, has emerged as a key strategy in this regard. This article explores the use of mainstreaming within the specific context of children's rights and uses its implementation in the specific context of the European Union's (EU's) asylum and immigration laws as a case-study to assess both its successes and its shortcomings. Using similar mainstreaming activities in the gender equality arena by way of illustration, the analysis questions, in particular, the capacity of mainstreaming: to accommodate the heterogeneity of child migrants as a group; to ensure appropriate representation and coordination in relation to children's rights at institutional level; and to deliver an adequate knowledge base to underpin decision making in the legislative process in relation to young immigrants and asylumseekers. The discussion concludes by pointing to some of the current deficiencies of children's rights mainstreaming, and speculating on its capacity to successfully promote the needs of young people in EU laws and policies in the future.