Photodegradation of tetracycline (TC) aqueous solution by FeO doped onto nano-clinoptilolite particles was investigated using a high pressure Hg lamp as radiation source. Nano-particles of clinoptilolite were prepared using ball-milling of micro crystals of zeolite. The pretreated nano-particles ion exchanged in a ferrous solution and the Fe(II)-exchanged form was calcined at 450°C. All samples were characterized by FT-IR, DRS, SEM and XRD. The degradation extent was determined via UV-Vis absorption spectroscopy and COD. Based on the study of the effect of key operating parameters, the optimal conditions were determined to reach the higher efficiency of the process. The best photocatalytic activity was obtained in presence of the catalyst containing 5.4% FeO.