The use of zeolite Y as a catalyst was strictly limited in the hydrophobic system due to its low Si/Al ratio. To increase the Si/Al ratio of zeolite Y, several methods have been developed although it remains a challenge. One of the methods to increase Si/Al ratio in zeolite is by means of dealumination using an acidic medium. In the present work, dealumination of zeolite Y was investigated using oxalic acid media in the presence of tetraalkylammonium (TAA) cations. The TAA cations employed in this work were tetramethylammonium (TMA), tetraethylammonium (TEA), tetrapropylammonium (TPA), and tetrabutylammonium (TBA). TAA cations successfully protect zeolite Y framework during the dealumination process, resulting in increased Si/Al ratio with relatively preserved crystallinity. Among the TAA cations, the ability to protect zeolite Y framework during acid treatment decreases as the length of the alkyl chain increase from TMA to TPA cations. However, the trend could not be applied at TBA cation. This nonlinear correlation is attributed to the interplay between electronic and steric properties of the TAA cations.