Goethite was synthesized by reaction of Fe(2)(SO)(3) and NaOH in aq. soln., sepd. by centrifugation, dried at 40 degrees C, classified to get the fraction with grain size below 0.1 mm and then used for adsorption of PO(4)(3-) ions (initial concn. up to 80 mg/L) from natural waters of various origin at 20 degrees C for 168 h. An adsorption equil. was reached after 48 h. The adsorption efficiency increased with increasing pH, water hardness, cond. and concn. of other cations present and was higher in the case of natural waters than in the distd. H(2)O. The process was better described bz Langmuir isotherm than bz Freundlich one.