Education in the mother tongue is the practical result of the Yugoslav model of multilingualism, which excludes any implication that one language may be inferior or superior to another? Education in the mother tongue has the effect of ensuring the exercise of human rights in general and the protection of national minorities in particular. 2 In this article we shall look at the problems arising from the various categories of instruction in the mother tongue, as well as their effects on pupils' achievement throughout the period in which they are taught in their mother tongue and later on when they continue their studies in a language that is not their own. We shall then consider the importance of teaching in the languages of the various nationalities 3 in preserving these languages and giving them a firm institutional basis. Lastly we shall discuss the influence of elementary education in the mother tongue on the degree of literacy attained by Yugoslavs whose mother tongue is one of the minority languages.