Polyploid organisms contain three or more sets of chromosomes in the same nucleus. It is an evolutionary driving force in plants. The goal of the generation of such synthetic citrus polyploid was to respond to the expectation of the market regarding quality traits and favoring adaptation to diseases and environmental constraints. Both auto- and allo-polyploidization in citrus can be beneficial in improving crop for specific attributes like quality, yield, or environmental adaption. Polyploidy may lead to large changes at the phenotypical, biochemical, and genomic levels. However, the molecular mechanisms at the origin of such changes remain poorly understood. The new advances, mainly driven by the fast progression of biotechnology, genomics, and bioinformatics predict an imminent boost for the development of the knowledge that is still required today for polyploidy to establish itself as a fundamental tool in the field of tree horticulture. This chapter reviews the methodologies to generate polyploids as well as the phenotypic traits associated with quality and adaptation.