We report the high energy gamma-irradiation induced structural transformations in nanocrystalline Mn1-xZnxFe2O4 (x = 0, 0.25, 0.5, 0.75 and 1) samples synthesized by solution combustion method using a mixture of fuels. All samples were exposed to a gamma radiation dose of 50 kGy. The gamma-irradiation decomposes the single phase cubic spinel (Fd-3m) structure of the samples into new stable phases. The pure MnFe2O4 sample transformed to Mn2O3 and Fe1-xO phases whereas the pure ZnFe2O4 sample retained its phase. For the samples with intermediate Zn-content gamma-irradiation facilitates the formation of stable alpha-Fe2O3 and ZnFe2O4 phases, along with amorphous MnO phase. The scanning electron micrographs demonstrate the complete change of the sample morphology with fusion of the particles after gamma-irradiation. Our results are important for the understanding of the stability and performance of the devices used in various technological applications near intense high energy radiation sources. (C) 2017 Elsevier B.V. All rights reserved.