Emerging plant viral diseases represent a significant burden to plant health, and their highest impact in Mediterranean agriculture is on vegetables grown under intensive horticultural practices. Intensive horticulture is very competitive and one of the most dynamic sectors in Mediterranean agriculture. The emergence of a new viral disease results from a complex interaction among several factors, including ecological changes of host and vector populations, and genetic changes due to the introduction of new crop varieties and the evolution of the viruses and/or vectors. A transnational consortium incorporating 12 research groups from 5 EU and 4 non-EU Mediterranean countries has been gathered to analyse different aspects of the ecology and biology of specific plant viruses, providing measures for the management and control of specific emergent viral diseases in Mediterranean horticulture and, importantly, a better understanding of the phenomenon of emergence itself. We will focus on a few undisputedly important case studies for Mediterranean horticulture, such as whitefly-transmitted geminiviruses in tomato and cucurbits, aphid-transmitted viruses in cucurbits and Pepino mosaic virus in tomato. Specific objectives of the project include (i) identification of host reservoirs for emergent viruses, (ii) development of advanced diagnostic tools, (iii) analysis of host-range determination and host-range modification, (iv) analysis of short- and long-range virus dispersion, including vector transmission and population genetics, (v) analysis of virus evolution, (vi) risks evaluation of virus emergence in a changing environment and (vii) development of sustainable strategies for the control of emerging plant viral diseases.