In this work, the effect of gamma radiation on the photoluminescent properties of thin films of binary nanocomposites MEH-PPV/C60 (polymer – fullerene C60) has been studied. Samples of pure MEH-PPV and MEH-PPV/C60 nanocomposites were synthesized in ratios of 9:1 and 3:1 on the mica and silicon substrates. Effect of type substrate on photoluminescence of pure thin films and nanocomposites were studied. Experimental data on dose dependences of the shape and intensity of the photoluminescence spectra after exposure of samples with doses up to 67 kGy were obtained and analyzed. The nonmonotonic nature of the change in the intensity of various spectral bands of the photoluminescence of nanocomposites with increasing dose and the absence of a shift of these bands was established. The obtained experimental results were interpreted from the standpoint of competition between the processes of crosslinking and breaking of polymer chains under the action of gamma irradiation. A practically important result of the study is the conclusion that MEH-PPV/C60 nanocomposites are highly resistant to gamma rays.