This paper investigates the technical efficiency of two samples of maize producers in eastern Ethiopia, one involving farmers within the Sasakawa-Global 2000 project and the other involving farmers outside this program. The study uses stochastic frontier production functions in which the technical inefficiency effects are assumed to be functions of the age and education of the farmers, together with the time spent by extension advisers in assisting farmers in their agricultural production operations. For the cross-sectional data obtained for the 1995/96 agricultural year, Cobb-Douglas stochastic frontiers are found to be adequate representations of the data, given the specifications of the translog stochastic frontiers for farmers within and outside the project. The empirical results indicate that farmers within the SG 2000 project are more technically efficient than farmers outside the project, relative to their respective technologies. The mean frontier output of maize for farmers within the SG 2000 project is significantly greater than that for the farmers outside the project. © 1998 Elsevier Science B.V. All rights reserved.