The formation of novel ZSM-5 zeolite/porous carbon composite from carbonized rice husk has been investigated using microwave- and conventional-hydrothermal reaction at 140–160 °C. ZSM-5 zeolite crystals were formed on porous carbonized rice husk by the dissolution and in situ crystallization of silica in the carbonized rice husk. Compared to the conventional-hydrothermal (C-H) formation of ZSM-5 zeolite, the microwave-hydrothermal (M-H) reaction led to increased rate of formation by 3–4 times at 150 °C. In addition M-H reaction yielded small particles of 0.3–5 μm. The surface area of ZSM-5 zeolite (without template)/porous carbon composite is 485.4 m 2/g, and this composite has both micropores and mesopores.