In agriculture, conventional production methods are called into question because of their impacts on the rapid degradation of non-renewable natural resources through overexploitation and on the environment in general. This study was carried out with a view to assess the sustainability of farms in the Mornag area, north Tunisia, using the Farm Sustainability assessment method universally called ‘IDEA method’ according to a determining factor: the level of education of the manager. On the basis of a sample of farmers, an empirical analysis allowed to assess the sustainability of different farms at three scales: agro-ecological, socio-territorial, and economic; and then compare the results between the different groups. Results showed that although the group of university farmers have an advantage in the components of the socio-territorial and economic scales, they are less so in the agro-ecological scale. This could be explained by the ambition of high-educated farmers to achieve higher profitability targets by adapting agricultural practices that are sometimes harmful to environment such as return to scale or intensive arboriculture. The other two scales (socio-territorial and economic) are more sustainable when the level of education is high. This reveals the significant impact of training and the acquisition of certain technical concepts on the agronomic and technical choices to be applied to raise the awareness of farmers on the importance of applying a more sustainable agriculture.