Copper(II) can be reduced in the presence of thiourea. Copper(I) complex containing thiourea ligand (tu) was encapsulated in intracrystalline cavities of the NaY zeolite via the ship-in-the-bottle technique. Characterization of the intrazeolitic complex was performed by X-Ray powder diffraction, FT-IR spectroscopy and diffuses reflectance methods. The data analysis indicates the Cu(I) complexes are encapsulated into the pores of the zeolite Y. Additionally, the surface texture evidence shows that successful immobilization of copper complex occurs inside of the zeolite.