Obsidians are naturally occurring glassy volcanic rocks which have great interest and are commonly preferred in engineering, medical and nuclear applications. In the present study, we aimed to determine the radiation attenuation parameters of Van-Erciş and Rize-Ikizdere obsidians in Türkiye in order to examine the radiation shielding potentials of the samples. The parameters were calculated in the range of 4keV-100GeV incident photon energies by Phy-X/PSD software. In order to make a meaningful evaluation about the shielding features of the samples, we compared the obtained mass and linear attenuation coefficients of the obsidians with those of a widely used shielding material, ordinary concrete. It was concluded that Ikizdere obsidian has higher shielding potential compared to Erciş obsidian, and both Ikizdere obsidian and Erciş obsidian have more shielding ability than that of ordinary concrete.