In recent years, a physiological understanding of the reproductive development process in fruit trees has accumulated through numerous molecular and genetic studies. Although the physiological traits of perennial or woody fruit trees often hinder studies of the mechanisms driving their reproductive physiology, such studies can provide important new findings in plant science, and beneficial information and new ideas for fruit production. This chapter reviews recent research on the physiology and genetics of reproductive development in fruit trees. Beginning with an introductory overview, the chapter goes on to include sections on the physiology and genetic analysis of reproductive meristem development, bud dormancy and flowering, sexual determination and development of flower structures. The physiology of pollination, fertilization and gametogenesis is also discussed. The chapter concludes with sections on the physiology and genetics of fruit development and phytohormones, and lastly, fruit maturation and ripening.