In this work, the effect of Gamma-irradiation was evaluated on the characteristics of mung bean (Vigna radiata) grains and starches, considering doses up to 5 kGy. For this purpose, the starch structure and properties were evaluated, as well as the grains’ hydration, germination and cooking. The irradiation process was able to change the characteristics of both mung bean starches and grains. The starch structure was partially changed, presenting smaller molecules and small changes in the granule morphology. No alterations were observed in the starch X-ray diffraction pattern, while lower pH was achieved. Considering the starch properties, it was observed lower water retention ability at 75 °C, lower apparent viscosity, higher paste clarity and, in general, harder and less viscous gels. The ionizing radiation accelerated the hydration, reduced the germination capacity and improved cooking time of the mung bean grains. The results proved the efficacy of using ionizing radiation, at the doses applied in this work, to desirably modify the mung bean starch and grains. © 2019 Elsevier B.V.