Abstract
Tanzania is a multilingual country with 150 ethnic languages spoken within its borders. The current sociolinguistic situation in Tanzania necessitates the continued use of Kiswahili as a unifying language. The majority of urban children now actually acquire it as their first language. It is also the language most frequently used in government offices, as well as in everyday activities countrywide. Despite the adoption of one of Africa's largest languages as an official language, the government has constantly insisted that English should remain the only medium of instruction at post-primary level, because of its tremendous power and prestige in the global market. The government's stance reveals a limited understanding of what a system for promoting bilingualism and biliteracy in education should involve. This article therefore investigates language policy development in education in Tanzania in terms of the sociolinguistic framework of bilingual education.