X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, 29Si and 27Al nuclear magnetic resonance and thermogravimetric analyses have been used to examine the synthesis of zeolite LTA and associated phases from metakaolinite. However, the synthesis product was controlled by the experimental method, taking into account that the classic hydrothermal transformation of the starting material produced a mixture of different zeolite-type structures, whereas the alkaline fusion approach promoted the crystallization of pure zeolite LTA.