Intensification and specialization of agriculture allowed increasing its productivity but also induced detrimental impacts on the environment and challenges for the economical viability of numerous farms. Association between livestock and crops, which was common in the past, is given consideration worldwide. It is regarded as a possible way for improving nutrient cycling while reducing chemical inputs, increasing sustainability of natural resources management, and also generating economies of scope. Mixed crop-livestock farming systems could therefore be a favourable alternative to specialized livestock systems. In this paper we address their environmental and economic advantages from a comparative assessment of real-life specialized and mixed farms in the region ‘Coteaux de Gascogne’ in Southwestern France. In this hilly region with frequent summer draughts, agriculture includes cattle and cash crop production. 47 % of the farms have a mixed crop-livestock production, the remaining been specialized either in crop (14%) or cattle production (39%). We made an exhaustive survey of the farms working land in a small area of about 4000 ha to assess local farming systems and farmers’ practices and strategies as regards farm and land management. We analysed farm diversity in reference to economic and environmental criteria. Our results pointed out an intensification gradient from low to high input farming systems amongst local farms. Beyond some general trends (e.g. dairy production more intensive than beef production), a wide range of management practices and intensification degrees was observed amongst farming systems of a similar orientation. Mixed crop-livestock farms appeared very heterogeneous as regards the use of external inputs. We compared intensification degrees in local livestock and mixed crop-livestock farms and discussed their respective advantages in reference to the feed cost per cow the income per work unit and the local challenges attached to land-use change.