γ-irradiated single crystals of amphi-chloroglyoxime were investigated by the electron paramagnetic resonance (EPR) between 123 and 400 K temperature. Paramagnetic species produced in the crystals were attributed to the R-HCNOH radical and relevant spectra were found to be temperature independent. The g -factor and hyperfine coupling constants of the R-HCNOH radical were found to be almost isotropic with the average values g = 2.0009, a CN = 31.89 G, a HC = 23.83 G, a OH = 9.49 G and the spin densities ρCN = %50, ρHCC = %50.