This article investigates mother tongue instruction (MTI) in Sweden and Denmark in a historical, comparative perspective, with a view to accounting for key differences in language policy enacted in educational fields. Whereas in Sweden, MTI is offered to linguistic minority children irrespective of their linguistic and ethnic backgrounds, in Denmark the right to state-sponsored MTI has been abolished for children of non-European descent. Moreover, while the policies of both states devalue skills in mother tongues other than the legitimate language of each society, this position is more pronounced in the Danish context. The article explores the two state's position on MTI, as expressed in policy as well as in discourse produced in the political and academic field of each state. It subscribes to Pierre Bourdieu's framework, within which state policy is conceived as the product of historical struggle and cross-field effects. The analysis shows that the national differences in MTI exist because of the differing ways in which agents from the academic vis-à-vis the political field have succeeded in imposing their visions in the bureaucratic field from which policies are produced. Ultimately, this circumstance explains why the Swedish discussion on MTI may be characterized as having been academically founded, while the Danish discussion has remained a matter of political consideration. In the latter case, we argue, it is particularly tangible that MTI is a politicized object of struggle, where agents seek to control the exchange rate of linguistic resources and, in effect, the social worth of different speakers.