In this work, laser-induced voltage (LIV) was used to assess three various crude oils using a 248 nrn ultraviolet laser. Under the same bias voltage, the peak of LIV (V-p) increased with the increase in the overall laser energy irradiating the surface of the sample. The increase in the bias voltage contributed to the improvement of V-p at the same laser energy. On the basis of our results, samples with more oxygen content generated more charge, which led to the higher V-p. Our research indicates that LIV is a suitable approach for the identification of various crude oils.