A single-line FIA system with a stream-sample splitting device for chloride determination is presented. The analytical method is based on the Fe3+/Hg(SCN)2/Cl−system and the absorbance of the red Fe(SCN)2+species monitored spectrophotometrically at 480 nm. Using a stream-sample splitting device, the recorded signal is composed of two merged peaks. Three calibration curves were obtained, once injecting the standard solution series, two using the maximum heights of P1and P2peaks and one using the height of T trough. The FIA system showed three linear responses to the concentration of chloride in the ranges 10-100 ppm (P1); 10-500 ppm (P2) and 20-1000 ppm (T), respectively. Also, it was capable of detecting chloride ions in different types of water with a throughput of 15 samples h−1and the RSD for 240 ppm of Cl−(n=10) were 1.67% (P1); 2.38% (P2) and 1.23% (T), respectively. The interference of several ions (commonly found in water) on the FIA outputs was investigated.