Many ethnoreligious-minority foster children in several western countries, including the Netherlands, are placed and permanently live with ethnically and religiously non-matched foster families (i.e., in trans-religious foster care). We examine whether and which moral dilemmas exist around the issue of how religion should be weighted in trans-religious foster care to provide ethnoreligious-minority foster children with healthy identity development. We applied a thematic analysis to 17 qualitative interviews (seven foster parent/foster child dyads and three foster parents) taken from two pre-existing datasets. We retrieved five moral dilemmas in trans-religious foster care placements, which are discussed in relation to the following ethical arguments: (1) pressure from birth parents and parents of foster children to abide by their religious praxis; (2) objections of the foster family to the faith of the birth family; (3) a switch to the faith of the foster family by the foster child; (4) challenges to the religious identity searches of foster children due to ethnoreligious boundary drawing between majority and minority groups; and (5) the impact of religious traditions on the bodily integrity of foster children. We argue that it is in the best interest of foster children to have a foster family who, when making (some) religious choices on their behalf, is sensitive to the particular child and their developing identity with regard to their religious ideas and beliefs. Foster families need support regarding religious reflection and religious self-determinism in their foster children.