In two major Italian islands, such as Sicily and Sardinia, located in the Mediterranean Sea, are concentrated almost 17% of total Italian farms. The purpose of this research was to assess since 2004 to 2014 by a quantitative non-parametric model such as the Data Envelopment Analysis the technical efficiency in farms belonging to the Farm Accountancy Data Network. Sardinian farms have had better results of technical and scale efficiency than Sicilian agricultural enterprises due to a different farm size and to an unsimiliar amount of financial payments disbursed by the Common Agricultural Policy.