A simple, selective and highly sensitive method has been developed for the determination of mercury(II) spectrophotometrically in presence of micellar medium using new three azobenzothiazol reagents, 2-amino-6-(thiazole-2-ylazo)-3-pyridinol [R1], 8-hydroxy-7-(thiazole-2-ylazo)quinoline-5-sulfonic acid [R2] and 1-hydroxy-4- (thiazole-2-ylazo)-2-naphthoic acid [R3]. The optimization of experimental conditions for the procedure has been studied. For the enhancement determination of mercury(II), Tween 80 and cyproheptadiene are used as micellar medium to increase the sensitivity of the procedure. The absorbance is measured at λmax of 617, 633 and 554 nm using universal buffer solution of pH 6.00, 7.13 and 4.97 for R1, R2 and R3 complexes with Hg(II) respectively. Beer’s law was obeyed in the ranges 1-10, 1-13 and 1-5 g mL-1 for R1, R2 and R¬3 complexes with Hg(II) respectively. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated. The interference of various ions has been studied in detail and the statistical evaluation of the experimental results is reported. The proposed methods have been successfully applied for the determination of trace amount of mercury(II) in environment water and food samples.