Currently, in the food industry, microwave energy is progressively outcome applications in numerous processing techs. A microwave, electromagnetic waves of precise frequencies ranging between 300 MHz and 3000 GHz, is a novel processing method that has been broadly applied in food processing fields. Thereafter, this innovative tool was explored by researchers as an upgrading method and has been effectively applied in blanching, cooking, thawing, pasteurization, drying, frying, extraction, and sterilization. This chapter outlines the principles and characteristics of microwave-assisted fish processing methods, and their impacts on drying, heating, and sterilization. Here, we discussed the impact of microwave-assisted fish processing methods on the quality features, microbial growth, nutritional and physicochemical composition of fish products. In addition, the advantages of microwave processing and a comparison against conventional methods were discussed. Interestingly, microwave processing ensures gaining time, effective yields, and energy with high preservation and could maintain sensory traits of the fish’s nutritional value. This chapter will provide evidence about these topics and their advances that could be motivating for food engineering and technology community. Moreover, the chapter will describe methods for microwave application in the fish industry.