Ordered silver iodide nanoclusters inside zeolite Y host were prepared by using a thermal diffusion method. The Y–AgI samples were characterized with powder X-ray diffraction, differential thermal analysis, X-ray photoelectron spectroscopy, adsorption technique and chemical analysis. The results show that silver iodide nanoclusters were situated in the ordered cages of the zeolite Y host. The results on the luminescence of the nanocomposites Y–AgI suggest that when the sizes of silver iodide nanoclusters are were very small, non-radiation surface recombination exceeds radiation process and the luminescence efficiency increases as the size of the silver iodide nanoclusters increaseds As the sizes of AgI nanoclusters increased, non-radiative surface recombination effect become equal to the radiation effect of the excitons. As the size of the nanoclusters of AgI in zeolite host further increases, the surface recombination of the nanoclusters becomes a major process.