AbstractThis chapter reviews the transmission of plant viruses by aphids, with particular emphasis on the virus-vector interactions, the attributes that make aphids such well-adapted vectors, the different modes of transmission, the determinants of transmissibility, the factors affecting virus acquisition and inoculation, control methods (e.g. use of virus-resistant or aphid-resistant genotypes, elimination of virus sources, and eradication of weeds, infected plants and volunteer plants), and prevention or reduction of virus spread by plant spacing and chemical, biological, cultural and integrated control of vectors among others.