Commercial and research interest in the irradiation of fresh fruit and vegetables as a market access treatment is growing. Irradiation has been approved for use in many markets as an approved phytosanitary/quarantine treatment to allow international trade. This chapter focuses on the effects of irradiation on key aspects of citrus fruit quality (internal and external quality and vitamin C content). The chapter considers the safety of irradiated food, uses of irradiation in postharvest horticulture, and the current state of trade in irradiated horticultural produce. The chapter reviews the effects of irradiation on citrus fruit quality. Finally, the chapter looks ahead to future research trends in this area and suggests further reading on the subject.