[en] The aim of this study is to investigate the efficiency treatment in removing Zn-65, Mo-99 and I-1 25 from an aqueous radioactive effluent. The wastes are currently being produced from hospitals, research institutes, clinics and universities. Effluent was spiked separately with each type of the radioisotope and was treated by the coagulation-flocculation process. By varying the chemical dosages (i.e., alum, soda ash, ferric chloride and coagulant aid) in the treatment, different decontamination factor values were obtained. Optimum dosages and types of chemical used to remove a particular radioisotope was determined. Results indicated that optimum pH value for removing Zn-65 in an effluent was pH 8. The highest decontamination factor value was 61. In removal of 1-125 radioisotope, ferric chloride was suitable as a coagulant that gives the highest decontamination factor value of 5.0. Treatment to remove Mo-99 radioisotopes was conducted in the laboratory and treatment plant scale. For Mo-99 radioisotope treatment by laboratory and Plant scale, the highest decontamination factor obtained was between pH values of 4.0 to 4.5. By extrapolation of both scales, the plant scale treatment does not vary significantly from laboratory scale. This indicated treatment dosages of chemicals for the Low Level Treatment Plant scale be deduced from the laboratory scale