Description:The assessment of sustainability at farm level has been growing in popularity over the last few years. This article contributes to this line of research by building up composite indicators for different facets—social, economic, environmental, and global—of farm sustainability using a methodological approach that combines data envelopment analysis (DEA) and multicriteria decision making (MCDM) methods, and assigns common weights to each individual sustainability indicator. This approach is applied to a database of 163 farms located in the Campos County, a region belonging to the dry lands of the Spanish Northern Plateau, using 12 individual indicators of sustainability. Our findings show that both economic and environmental composite sustainability indicators are positively correlated, but that this is not the case for the social indicator. We also check the influence of a set of variables on farm sustainability using bootstrapping statistical techniques, and showing that increasing farm size, membership in agricultural cooperatives and farmers’ medium and upper agricultural‐specific technical education, all exert a significant positive influence on sustainability. These results provide clues for policy makers that intend to design sustainability‐increasing structural agricultural policies.