This article analyses the way Australian and United States of America (USA) governments used the notion of the best interest of the child to remove Aboriginal and Native children respectively from their families and communities. Both governments relied on legal means to achieve the assimilation of children within the mainstream culture in order to annihilate Aboriginal and Native culture. On the one hand, the children were targeted because of their malleability and capacity for adaptation without influencing the mainstream culture. On the other hand, the chance of survival for their community was very thin without them. With regard to Australia, the process began as early as when the first settlements were established as Aboriginal women and children were kidnapped for economic and sexual exploitation. The protectorate system was thus established in the 1830s to assure their protection on reserved lands administered by a Chief Protector. In the case of the Native Americans, the assimilation policies were carried out with the boarding school system and the placements in white adoptive and foster homes. Both governments had shown the limit of their role as parens patriae when ethnic issues were at stake.