The global horticultural sector faces a serious threat from the cucumber mosaic virus (CMV) because of its rapid spread and expanding host range. This virus poses a significant problem, because it can infect crops at all stages of growth. CMV belongs to the genus Cucumovirus within the family Bromoviridae and is one of the most widespread and destructive pathogens. It is transmitted by various aphid species in a nonpersistent manner. The symptoms of CMV infection vary depending on the host species or the specific CMV strain and may include mosaic or mottling patterns, stunting, ring spot formation, chlorosis, dwarfing, leaf malformation, flower and fruit distortion, and systemic necrosis. Disease management can be achieved to some extent through cultural, chemical, and biological methods, as well as by utilizing resistant varieties. In this chapter, we provide an in-depth exploration of CMV distribution, genome organization, epidemiology, and management.