The objective of this study was to examine zeolite Y and natural zeolite as potential fillers in medium density fiberboard (MDF) production with urea formaldehyde (UF) and melamine formaldehyde (MF). Three different zeolite contents were used as 4%, 8%, and 12% based on dry resin amount. The produced panels were evaluated in terms of modulus of rupture, modulus of elasticity, internal bonding, thickness swelling, water absorption, limiting oxygen index (LOI) and thermogravimetric properties. Based on the findings in this study, the mechanical properties of MDF samples were improved with the increment ratio of zeolite. Besides, the dimensional stability of the zeolite-added samples increased. There was no significant effect on the thermogravimetric and derivative thermogravimetric curves of the samples with adding zeolite but some improvements were observed in LOI level and charring rate of the samples. It appears that overall properties of the MDFs with MF were higher than those of MDFs with UF.