Papaya orchards throughout most of the world are severely damaged by the destructive disease caused by the papaya ringspot virus (PRSV). PRSV-resistant papaya expressing the coat protein gene (CP) of PRSV have been used in Hawaii to control PRSV since 1998. This chapter presents the experimental steps involved in the development of transgenic papaya, including transgene construction, transformation, and analysis for virus resistance of the transformed papaya. We also describe the important factors that enabled deregulation, commercialization, and adoption of transgenic papaya to occur in Hawaii in a timely manner. Transfer of this technology to other countries with the similar goal and the development of transgenic papaya in other regions of the world also are described.