A high AI-Si Chinese fly ash from Dou He power plant (Tangshan city, Hebei Province, Eastern China) was selected as starting material of the zeolitisation process. Zeolitic material was obtained by conventional alkaline activation using NaOH and KOH solutions. The process of synthesis was optimised by applying a wide range of reaction temperature, time and activation reagent concentrations. A high solution/fly ash ratio was used in order to dissolve highly resistant Al-Si phases such as mullite. High yields were obtained with both KOH and NaOH solutions. Final products reached a cation exchange capacity (CEC) of up to 2.3 meq g(-1). Major zeolites obtained with a high CEC were: NaP1, KM and F-linde zeolite. The low contents of major impurities of this fly ash enhance the potential application for the synthesis of zeolites for waste-water treatment.