Sinthesis experiments have been carried out in order to obtain zeolites form kaolinics clays. The method consisted in a treatment of kaolins (either naturals or thermically treatest at 600 and 1000 °C), with sodium and potassium hidroxide at 80°C. The reaction products were studied by XRD. After 32 days with a NaOH solution 1 N, the natural and both heated kaolinites gave Zh zeolite (ASTM 16-612) as reaction product. Besides, with the former it was also obtain a ZK zeolite (ASTM 18-1198) and with the 600°C heated kaolinite a Na-A zeolite (ASTM 11-590). In a second stage the sinthesized zeolites were treated with a KOH solution 1 N for 32 days. Only the zeolite formed from natural kaolinite reacted giving a zeolite phase N. With the KOH 1 N solution the 1000 °C heated kaolinite rerained unchange and the 600°C heated one gave a zeolite phase N. The natural kaolinite changed first (32 days) to a potassium chabacite (ASTM 12-194) and later (75 days) to a sodalite phase N (ASTM 23-1313). In the second stage, with the NaOH 1 N solution only K-chabacite obtained from the natural kaolinite changed to a Na sodalite (ASTM 20-1070). Others remained unchange.Aznar et al. (1985), sintetizaron ceolitas A y X a partir de caolines previamente calcinados (activados térmicamente) a 600 °C, tratados con hidróxidos alcalinos a 100°C. Con las muestras naturales obtuvieron sólo un feldespatoide hidratado (hidrosodalita). En el presente trabajo se realizaron experiencias a 80°C con caolinitas tanto naturales como tratadas térmicamente a 600°C y a 1000°C, con soluciones 1 N de NaOH y KOH, lográndose en todos los casos, la cristalización de diferentes tipos de ceolitas. Se informa sobre los resultados de ensayos tendientes a establecer la posibilidad de obtener artificialmente ceolitas de diferentes tipos a partir de materiales arcillosos caolínicos de baja calidad, por ejemplo, de los minerales de baja alúmina y elevado hierro y titanio que se deshechan en las explotaciones mineras. Además se demostró que es posible controlar el tipo de ceolita forrada, cambiar su composición y reactivarlas luego de determinado uso.