This study investigated ion-irradiation performance and mechanical behavior of high-entropy metallic glasses (HE-MGs) irradiated at room temperature. The critical fluence for blister formation in ZrTiHfCuBeNi HE-MGs was higher than ZrTiHfCuBe HE-MGs because of the larger mixing entropy and negative mixing enthalpy. The ZrTiHfCuBeNi HE-MGs maintained a more moderate hardness value than ZrTiHfCuBe HE-MGs at a fluence of 1.0 x 10(18) ions/cm(2), implying a better irradiation tolerance and capacity of helium atoms. There was not a serrated flow or pop-in event that occurred in the HE-MGs after ion irradiation, which indicated that the formation of serrations was restricted. The total displacement and peak intensity in the creep relaxation spectrum increased as the ion fluence increased. The ZrTiHfCuBeNi HE-MGs exhibited a lesser change in peak intensity and relaxation time. This study demonstrated that HE-MGs may exhibit a favorable response to high levels of helium implantation, which exhibits potential uses under extreme irradiation conditions. (C) 2019 Elsevier B.V. All rights reserved.