The influence of gamma irradiation on the properties of compatibilized linear low-density polyethylene/magnesium hydroxide (MH)/sepiolite composites has been investigated. Vinyl triethoxy silane and maleated polyethylene have been used as compatibilizers. The compatibilizing effect in the composites is confirmed by the Fourier transform infrared spectra, which showed the presence of additional chemical bonds, which are responsible for the enhanced polymer-filler interaction. As a result, the miscibility of the polar additives into the nonpolar polymer matrix is enhanced. The scanning electron micrographs revealed that the additives are well embedded and uniformly dispersed in the polymer matrix without any voids. The known thermal decomposition temperature of MH (approximate to 350 degrees C) is also increased in the compatibilized composites. In addition, 150 kGy irradiated composite showed a remarkable improvement of 37 degrees C in the onset degradation temperature of unirradiated composite. Furthermore, the formation of radiation crosslinked structure in the composites also improved the mechanical properties of the composites. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013