A new gemini surfactant, [C 18 H 37 (CH 3 ) 2 –N + –(CH 2 ) 3 –N + –(CH 3 ) 2 C 18 H 37 ]Cl 2 (C 18-3-18 ), has been successfully used as the mesopore directing agent in the hydrothermal synthesis of mesoporous ZSM-5 (MZSM-5). The synthesis of MZSM-5 was realized with a low temperature crystallization process at 130 °C. The amount of C 18-3-18 used in the synthesis affected the relative crystallinity and the textural properties of the obtained MZSM-5. Detailed investigation showed that the formation of MZSM-5 followed a crystallization transformation process. The use of C 18-3-18 resulted in the formation of mesoporous material during the early stage of the synthesis, which was converted into MZSM-5 crystals templated by tetrapropylammonium bromide to form the MFI phase. As the synthesis proceeded, the MZSM-5 crystals aggregated into particles by weak interactions. This work shows that C 18-3-18 can be used as a mesopore directing agent, which could provide a route for the synthesis of other mesoporous zeolites.