The synthesis of low-silica X (LSX) zeolite was carried out on porous, fired kaolinite pellets. The effects of changes in initial substrate porosity, aluminum concentration in the starting mother liquor, and use of seed solutions to promote zeolite crystallization have been examined. The results show that pellet shape preservation depends on the pellet starting macroporosity. A minimum SiO2/Al2O3 ratio in the batch for pure LSX crystallization was established, and it was also proved that seed utilization enhances the zeolite formation on the pellets but produces simultaneously powdered zeolite in the solution.