Composite zeolites containing ZSM-5 are known to be very active for catalytic conversion of syngas into gasoline range hydrocarbons under Fischer-Tropsch synthesis. In this work, a novel MOR/ZSM-5 composite zeolite with immersed Co particles was successfully fabricated under a facile solvent-free synthesis method. The final catalysts were characterised by XRD, SEM and TEM procedures to evaluate the structural properties and morphologies of Co@MOR/ZSM-5. Variation in the crystallization time played a vital role during zeolite synthesis. Perfect crystal structure for solvent-free Co@MOR/ZSM-5 was found at 72 h of crystallization time and proved to exhibit the greatest gasoline selectivity of 72.3%. This composite zeolite synthesized by solvent-free method with outstanding performance, has all potential to act as highly effective heterogeneous catalyst in the near future.