Tellurium was determined spectrophotometrically at 635 nm and pH 5.3 based on its catalytic reduction of Toluidine Blue in the presence of Te(IV) by using a flow -injection system. Under the optimized experimental conditions, the detection limit is 60 ng/ml of tellurium ion and the linear range is 80–3800 ng/ml (110 μl, injection). The relative standard deviation of 10 replicate measurements is 1.5% for a 1.5 μg/ml of tellurium. The sampling rate is 25 h-1.