More than 90 per cent of Italian farms have a usable agricultural area of less than 9 ha, even if over time there has been a growth of the average agricultural area per farm as a consequence of rural out-migration. This paper compares, using a nonparametric model, the technical efficiency of smallholder family (diretto coltivatrice), co-operative and limited company farms during the period 2000-2011. The diretto coltivatrice farms and the co-operative farms had higher levels of scale efficiency than the limited company farms, with a scale efficiency value equal to 100 per cent in ten years out of twelve. The average technical efficiency of diretto coltivatrice farms was higher than those of co-operative and limited company farms. The second part of the quantitative analysis used the self-organizing maps (SOM) proposed by Kohonen. The SOMs indicated that the size of the agricultural area has a direct impact on the technical efficiency of farms and on their level of income.