The electron paramagnetic resonance (EPR) of gamma-irradiated single crystals of cholesteryl methyl carbonate (C29H48O3) has been studied for different orientations of the crystals in a magnetic field. EPR spectra of cholesteryl methyl carbonate (C29H48O3 irradiated by Co-60-gamma were recorded between 125 K and 300 K for different orientations of the crystal in the magnetic field. The spectra were found to be temperature independent. In C29H48O3 single crystal,. the radiation damage centers caused by a Co-60-gamma source were determined as CH3CH2CH radical. For CH3CH2CH radical, a value of spectroscopic splitting factor g was calculated and experimentally results were supported by simulation program (WinEPR). (C) 2014 Elsevier B.V. All rights reserved.