Mediterranean grasslands (including rangelands, pastures, meadows, fodder crops) are important resources covering up to 48% of the whole region. Although these ecosystems are a key element in the production of high quality animal products and in the livelihoods of producers, they provide a range of ecosystem services besides forage production, such as biodiversity conservation, habitat for wildlife, carbon fixation, prevention of erosion and nutrient storage. There are socio-economic and environmental differences among the different Mediterranean regions, but they share common issues on grasslands sustainability and research. Multidisciplinary investigations are needed to identify the best-adapted and most productive grassland species and mixtures along with the most appropriate grazing management to produce high-quality livestock products. Multidisciplinary research is also needed to monitor the pastoral resources, environmental outputs and ecological services associated with Mediterranean grasslands, to ensure a better understanding of their complexity and to inform management decisions and measures for climate change mitigation. More on-farm experimentation and participatory knowledge transfer to farmers are also required. This publication is an outcome of the 15th Meeting of the FAO-CIHEAM Inter-regional Cooperative Research and Development Sub-Network on Mediterranean Pastures and Fodder Crops titled “Ecosystem services and socio-economic benefits of Mediterranean grasslands”, organised in Orestiada (Greece) from 12 to 14 April 2014, by the Mediterranean Agronomic Institute of Zaragoza/International Centre for Advanced Mediterranean Agronomic Studies, the Democritus University of Thrace, the Aristotle University of Thessaloniki and the Hellenic Range and Pasture Society. These Proceedings include 89 papers presented at the Meeting, covering a range of topics allocated into four sessions: (1) Managing ecosystem services and livestock production in the Mediterranean region; (2) Improvement of range, pasture and forage species including alternative uses; (3) Socio-economic benefits of sustainable grassland management; (4) Rehabilitation of Mediterranean grasslands; and a Round Table on “Connecting research, policy and stakeholders challenges for the sustainability of grasslands”.