This paper focuses on assessing the benefits of research expenditures on maize production in South Africa. Both the production and supply function approaches are used to calculate elasticities of research expenditure on output and yield. Cointegration is used to establish long-run relationships between variables in these models. The lag structure of R&D expenditures on output is examined making use of the unrestricted, polynomial, beta and gamma distributions. The coefficients of these lag distributions were then used to calculate a rate of return to maize research expenditure, which was estimated as being between 28% and 39% per annum. These rates of return are high, mitigating in favour of more research expenditure rather than less.