Colossal magnetoresistive La0.7Ca0.3MnO3 (LCMO) films with improved magnetoresistance properties have been grown at relatively low temperatures using an ultraviolet-assisted pulsed laser deposition technique. In this technique, a low pressure Hg lamp having a fused silica envelope, which allows more than 85% of the emitted 184.9 nm radiation to be transmitted, is added inside the growth chamber during pulsed laser deposition of LCMO films. Magnetoresistance (MR) measurements carried out on LCMO films grown under identical conditions barring the presence/ absence of UV radiation during thin film formation have shown that the MR ratio of UV-assisted grown LCMO films is nearly two orders of magnitude higher than that of LCMO films grown without UV. The improvement in magnetoresistive properties of LCMO film deposited in the presence of UV is assumed to be related with improvement in oxygen content, oxygen homogeneity, and crystallinity. Evidences supporting this assumption are obtained from analysis of spectra recorded using x-ray photoelectron spectroscopy and Rutherford backscattering measurements.