Radiation‐induced defects in a new second harmonic generation material, lithium vanadate single crystal, have been studied by electron paramagnetic resonance (EPR) and optical absorption measurements. EPR detects two intense signals due to intrinsic O- and impurity‐associated CO-3 trapped‐hole centers at 77 K, but no such signal in the case of trapped‐electron centers. The EPR signal of impurity Fe3+ ions is suppressed by 77 K irradiation. Low‐temperature irradiation produces three optical absorption bands peaking at 3.14, 2.0, and 1.56 eV. It has been concluded that some of the free electrons produced by irradiation are trapped by Fe3+ ions at low temperatures. After annealing at room temperature all the optical absorption bands disappear, although the EPR signals of CO-3 trapped‐hole centers and unidentified electron‐type centers at g=1.96 remain stable up to 330 K. © 1995 American Institute of Physics.