Abstract - In the last years air transport industry underwent a strong deregulation trend worldwide. Particular attention was put by US as well as EU policy makers to develop higher competition between potential suppliers of ground handling services. Hence, it is taking growing relevance the decision by airports’ managers at any airport size to fully or partially out/in-source handling operations. Furthermore, commercial business is becoming increasingly interesting in light of revenues diversification opportunity. Using a stochastic input distance function approach we develop a model to test whether economies or diseconomies of scope among outputs occur as well as to evaluate the technical and scale efficiency conditions on a sample on Italian small and medium airports. Scope diseconomies connected to operational size are found between airside aeronautical and handling activities. On the contrary, scope economies occur anywhere between aeronautical and commercial operations. This paper improves the existing literature under two points of view. First it provides evidence on the highly debated theme of outsourcing and diversification opportunities for airports. Secondly, it uses a methodology which allows to get estimates without incurring in the a-priori assumption of overall cost-minimisation behaviour.