Various MX (M = Cd, Zn, and Mn, X = S and Se) semiconductor quantum dots (QDs) were prepared in zeolite Y. While the QDs are readily expelled from zeolite interior upon exposure, of the MX QD-incorporating zeolite Y ([MX]-Y) to the ambient atmosphere due to moisture adsorption, they remain tightly confined within zeolites even after exposure to the moist atmosphere for several weeks when the surfaces were silylated with various silylating agents. This methodology will facilitate the characterization of the zeolite-encapsulated QDs and the application of QD-incorporating zeolites.