The main factors concerned with cassava breeding are described, such as origin and domestication, botanic classification and relationship with other species, reproduction mode and floral biology, factors that influence flowering, factors that affect hybridization and seed production, genetics and cytogenetics, qualitative trait heredity, selection criteria for yield, hybridization techniques, general and specific breeding objectives, breeding methods, diffusion of new varieties, current state of breeding, main results and impacts, the future of breeding and cultivars recommended in Brazil. The main results obtained at the national and international level in the areas of germplasm and cassava genetic improvement are presented. A list is included with the description of the cultivars for the Northern, Northeastern, Southeastern, Central-Western and Southern regions of Brazil.