Abstract: A flow injection method for fluorimetric determination of phenols in river water and waste water was developed. The fluorescence of phenols was measured at 299 nm (excited at 269 nm).The new method is simple, rapid and sensitive. The sampling frequency is 120 h_-1.The calibration graph is linear up to 100 ppb phenol concentration and the detection limit is 0 .7 ppb. This method was compared with an official 4-aminoantipyrine (4-AAP)method.