ZSM-5 has emerged as versatile catalyst for petrochemical industry due to its shape selectivity and strong acid strength. To produce olefins from methanol, optimized distribution of catalyst acid sites plays an important role. Acid treatment of ZSM-5 was performed for dealumination using four different acids, namely boric acid, nitric acid, phosphoric acid and tartaric acid at three different concentrations (0.1 M, 0.5 M and 1.0 M). All experiments were performed at a space velocity of 4 h–1, 500ºC and 1 atm pressure. Physical and chemical changes in catalyst were determined using XRD, BET, ICP-AES. It was observed that the ZSM-5 treated with 1 M boric acid emerged best amongst all in terms of olefins selectivity. Order of olefin selectivity with acid modified catalysts was observed as 1 M BZSM (83%) > 0.1 M TZSM (77%) > 1 M TZSM (75%) > 0.5 M NZSM (73%)> 0.1 M BZSM (69%) > ZSM (68%).