Schooling has been shown to provide substantial externality benefits by increasing farm output and shifting the production frontier outwards. This paper investigates the role of schooling at the household- and site-levels in the adoption and diffusion of agricultural innovations in rural Ethiopia. We find that household-level education is important to the timing of adoption but less crucial to the question of whether a household has ever adopted fertiliser, i.e., early innovators tend to be educated and to be copied by those who adopt later, obscuring the relationship between education and adoption at the household-level. By contrast, site-level education appears not to affect the timing of an innovation’s introduction to the site, but does influence the extent of diffusion. Thus, there are two externality effects: educated farmers are early innovators, providing an example which may be copied by lesseducated farmers; and educated farmers are better able to copy those who innovate first, enhancing diffusion of the new technology more widely within the site.