This article deals with language-in-education policy selection in South Africa, and aims to provide the general information needed by school governing bodies to make informed and justifiable decisions about language-in-education policy. The following matters are dealt with: the need for the medium of instruction to be a language which learners know very well; the relevance of arguments offered in support of selecting English as medium of instruction in South Africa; arguments in favour of using African languages as media of instruction; the capacity of the African languages to function as media of instruction; and the costs of using these languages in this function.