We review the major viruses in sweetpotato in different regions of the World, particularly Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato feathery mottle virus (SPFMV), comparing impacts on yield in single and complex infections and incidences of all the major viruses affecting the crop. How cultivars are generated, together with virus resistance, are also covered, especially for Africa. The synergistic (SPCSV + SPFMV) sweet potato virus disease (SPVD) is amongst the most dramatic diseases of sweetpotato but its overall yield impacts may not be as high as is generally assumed. It is constrained by resistance, roguing and selection of asymptomatic planting material. Instead, the cumulative impact of individual and combinations of asymptomatic viruses may be globally greater. These include sweepoviruses and various potyviruses of which the commonest is SPFMV. We identify a number of aspects of virus cleaned planting stocks including re-infection rates that need investigating before their use is considered as sustainable in developing countries. Popular East African cultivars appear to sustain their long term survival by reverting from asymptomatic infection, we describe the likely biochemistry, draw parallels with other crops and conclude that breeding for this attribute will be the best strategy for achieving long term control of most sweetpotato viruses.This article is protected by copyright. All rights reserved.