Among the most devastating pathogens, plant viruses are responsible for considerable losses of most agronomically important crops in the fields. The development and use of cultivars that are genetically resistant to viruses is an efficient strategy to tackle the problems associated with virus diseases. Recently, important advances have been made in our understanding of the molecular nature and mechanisms associated with natural recessive and dominant resistance genes, as well as in the antiviral defence system based on ribonucleic acids, referred to as RNA silencing. In this review, the authors summarise current knowledge about the defence mechanisms that prevent or limit viral infection in plants and discuss the likely collaboration of these different antiviral strategies insuring the resistance of the whole plant.