NaY zeolite membranes were prepared on porous mullite supports by secondary hydrothermal growth for pervaporation separation of thermal-sensitive methanol/methyl methacrylate (MMA) mixtures. Effects of synthesis parameters (synthesis time, gel composition, aging treatment and silica source) and separation conditions (feed temperature and composition) on the separation performance of NaY zeolite membranes were investigated. Under optimized membrane synthesis conditions (6.5 h crystallization time, 10-16 h aging time at 303-323 K. and gel composition of 1SiO(2): 0.04Al(2)O(3): 0.88Na(2)O: 40H(2)O), NaY zeolite membranes without the impurity phase of P-type zeolite could be formed on the porous supports. The best membrane displayed fluxes of 0.55-2.35 kg m(-2) h(-1) and separation factors of 1000-3600 for the 5-50 wt.% methanol/MMA mixtures at 323 K. The preparation of NaY zeolite membranes under optimized conditions showed a good reproducibility. The high methanol/MMA pervaporation separation performance of NaY zeolite membranes can be attributed to the selective sorption and molecular sieve of zeolite layers. (C) 2012 Elsevier B.V. All rights reserved.