This chapter discusses the history, principles, and microcidal effects of irradiation as well as how irradiation influences quality, sensory characteristics, and consumer acceptance of meat products. The combinations of physical and/or chemical treatments that can improve the efficacy of irradiation and the quality and consumer acceptance of irradiated meat products are also discussed. The volatile profiles and sensory characteristics of amino acids clearly explained why irradiation odor was different from lipid oxidation odor, and why lipid oxidation was responsible for only a small part of the off-odor in irradiated meat. The color changes in irradiated meat vary significantly depending on various factors such as irradiation dose, animal species, muscle type, and packaging type. Market simulation studies showed that the consumer acceptance of irradiated meat and poultry increased when the participants received additional information about food irradiation.