A non-neutral stochastic distance function model is used to examine whether output specialization has an impact on the economic performance of vegetable producers in Benin. Specialization is assumed to have an effect on the production frontier and on the distance to the production frontier (technical inefficiency). The technology is found to exhibit diseconomies of scope, indicating that vegetable producers have an incentive for specialization. At the same time, the degree of specialization has a positive effect on technical efficiency. From a policy perspective, the findings imply that current government policies to encourage diversification may lead to a lower performance.