Thin layers of silicalite-1 were grown on H-ZSM-5 crystals. Silicalite-1 crystals of < 100 nm formed on the ZSM-5 crystals and grew along the crystal surface (see Figure). The single-crystal-like composite catalyst showed excellent para-selectivity of 99 % in the alkylation of toluene with methanol, and is expected to develop as a new shape-selective catalyst.