One of the most promising materials for X-ray and gamma ray detectors are cadmium telluride (CdTe), and cadmium zinc telluride (CdZnTe) compound semiconductor crystals [1, 2]. The main reason for this is the possibility to use those materials at room temperature. However, Te inclusions, crystal twins, dislocations, grain boundaries and other defects degrade crystal performance as radiation detector. Several researchers have studied a possibility to improve crystal quality by CO2 laser irradiation [3, 4]. However, this method has some disadvantages - processing time of about 100 h and damage of the crystal surface. We have studied the influence of laser radiation on CdZnTe crystal electrical properties and radiation detector parameters. CdZnTe crystal was grown by vertical gradient freezing method and had high concentration of non-controllable impurities and Te inclusion. CdZnTe samples where treated by Nd:YAG (λ=1064 nm) laser to decrease defect influence on electrical properties. Current voltage characteristic measurements (IV) were performed to detect changes in electrical conductivity. IV characteristic showed that the sample resistivity increased after irradiation by 2·104 laser pulses. This effect is more pronounced with higher Te inclusion concentration. Moreover, energy-dispersive X-ray spectroscopy did not show any changes of chemical composition, but measurements of 241Am radiation spectrum showed increase of peak to valley ratio. Laser treated CdZnTe detectors showed reduction of leakage current, improved spectral energy resolution and peak to valley ratio.