Zeolites NaZSM-5 and NaY as hosts for producing nanoscale silver iodide guest were studied with the goal of investigating the optical properties of the prepared host-guest nanocomposite materials. The host-guest nanocomposite materials of NaY–AgI and (NaZSM-5)–AgI were prepared by a heat diffusion method. The nanocomposite materials prepared were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), X-ray photoelectric spectroscopy (XPS), and adsorption. The properties of the diffuse reflectance absorption spectra and the surface photovoltage spectra of the prepared nanocomposite materials were investigated. The quantum confinement effect of the channels of zeolites made the prepared host-guest nanocomposite materials show some interesting optical properties. This makes the investigated nanomaterials suitable for use as quantum electronic and optoelectric materials.