Titanium dioxide and zinc oxide (TiO2:Nb and ZnO) are the wide band gap metal oxide semiconductors with numerous applications in science and technology[1]. The crystal TiO2 is known to form many polymorph phases, but the most studied TiO2 polymorph phases are anatase, rutile and brookite. It is known that the anatase is more favorable for photo catalytic applications, while the rutile exhibits better optical and electrical performance [2]. Recently, we have shown the possibility to form Zn nanoparticles in ZnO crystal using Nd:YAG laser radiation [3]. In this study, the effects of laser radiation on TiO2 and ZnO crystals were investigated with aim to show the possibility of phase transitions rutile–anatase in TiO2:Nb and metallic Zn phase formation in ZnO crystals by Nd:YAG laser radiation.