The extensive use of foreign languages in schooling might have an important role to play in the poor educational outcomes observed on the African continent. Exploiting the language policy change of 1994 in Ethiopia as a natural experiment, we estimate the effects of provision of mother tongue instruction on the largest ethnic group in the country. Our results suggest that provision of mother tongue education led to an increase of 0.75 to 1 year of primary schooling in the a....ected cohort. Moreover the entire increase in the years of schooling can be attributed to the intensive margin of education. The language policy change, conditional on enrolment, increased the percentage of people completing 6 years or more of schooling by 31%. Applying our findings to a set of African countries shows that even after accounting for the costs of provision, introduction of mother tongue instruction imply potentially large benefits and increases the percentage of population completing primary schooling by as much as 15% points. These finding have important policy implications at a time when surging enrolment rates and already stretched educational budgets in the African continent imply need for solutions which can increase the quality of education without requiring huge capital or infrastructural outlays.