A simple flow injection photometric method for the determination of copper was developed based on the formation and liquid-liquid extraction of the analyte-bathocuproine-perchlorate ternary complex. The analytical reaction of complex formation is integrated with the continuous liquid-liquid extraction procedure. A hollow fiber-type membrane separator was specially constructed for the determination. The analytical properties like sensitivity, precision, accuracy and rapidity were evaluated. The sensitivity of the method depends on the injection volume. By using an injection volume of 0.6 ml, the detection limit (3σ) found was 15 ng ml−1copper, with a determination range of 48 - 3000 ng/ml. The repeatability of the method, expressed as the relative standard deviation, was in all instances less than 3.0%. The sampling rate was of 20 h−1. The accuracy of the method was tested with certified reference materials, and the mean error was calculated to be less than 5%. The method was successfully applied to the determination of copper in river water.