This study investigates the relationship between farm size and technical efficiency for maize production in Rwanda. Since levels of technical efficiency tend to vary considerably across farms in sub-Saharan Africa, with a mixture of both inefficient and fully efficient farms, the use of the conventional stochastic frontier method is not appropriate. In this paper, we apply a zero-inefficiency stochastic frontier method that manages both efficiency and inefficiency in the studied sample. The average technical efficiency of maize farms for the full sample is estimated at 0.64, demonstrating that maize output can be improved by approximately 36% without increasing the proportion of farm inputs used. Regarding the relationship between farm size and technical efficiency, the study results show a positive relationship between farm size and technical efficiency for maize production in Rwanda. Thus, the enforcement of land reforms such as land consolidation and enhanced aggregate productivity growth are needed. The results also indicate that education, cooperative membership, extension services, access to credit, off-farm income, land tenure, and livestock ownership have significant and positive effects on technical efficiency.