Cacao swollen shoot virus (CSSV) is the only virus disease of cacao that is prevalent and damaging. CSSV is a dsDNA virus of the genus Badnavirus and the family Caulimoviridae transmitted by several species of mealybugs. The historical emergence of the disease is closely associated with the establishment of cacao cultivation in West Africa as it appeared soon after the introduction of the cacao in West Africa and remains endemic to this area. The disease is likely due to several host shifts from indigenous hosts. We can additionally conclude from the high molecular variability of the virus that the disease consists of a complex of viral species. Although the disease spreads slowly, eradication campaigns have failed to contain the disease which continues to emerge in new West African regions.