Starch is one of the most studied natural polymers due to its widespread and applications as well as to the global interest regarding renewable, cheap, and easy to process resources. The native form of starch is frequently subjected to different processing methods in order to modify its structure and thus to obtain some functional properties suitable in specific industrial applications. Radiation-based method is a "green tool" for modification of natural polymers, such as starch, cellulose, pectin, and chitosan, alginate, having advantages over conventional methods that involve chemical agents associated with environmental toxicity. Radiation processing of natural polymers involves a simple, ecofriendly, and fast process that has harmless feature and provides advanced materials with unique properties. The chapter intends to be an overview of the major findings in the last decade concerning the starches modified by ionizing radiation processing. Therefore, aspects strongly related to changes in physicochemical, functional, and structural properties of starches from various botanical origins are approached. The main key points of this topic are highlighted by a critical evaluation of the mentioned aspects and future perspectives are suggested.