This paper investigates the effect of the organisational structure of primary and secondary education systems on their productive efficiency. We use stochastic frontier analysis to estimate efficiency for 18 OECD countries in 2000 and 2003. Organisational structure is explored through two analytical components: the share of public/private providers in the system and the degree of decentralisation of public providers. The share of public providers is found to exert a negative effect on efficiency whereas the degree of decentralisation of public providers is found to exert a positive effect on efficiency.