Pyrimidine-2-thiols are reported to be good analytical reagents for the spectrophotometric determination of metal ions. In the present work 1-amino-4,4,6-trimethyl (1H,4H) pyrimidine-2-thiol(1-amino TPT) was used as an analytical reagent for the extractive spectrophotometric determination of bismuth(III). The optimum extraction conditions were evaluated by studying parameters like acidity, equilibration time, reagent concentration and stability of complex. 1-amino TPT in chloroform gives an orange coloured complex with bismuth(III) in 4.5 to 6.0 M perchloric acid medium. The absorption spectrum of bismuth(III)-1-amino TPT complex shows maximum at 470 nm and obeys Beer's law in the range of 7-24 ppm. The molar absorptivity and Sandell's sensitivity were 6.501x10(3) L mol(-1) cm(-1) and 32 ng cm(-1) respectively. The composition of the bismuth(III)-1-amino TPT complex was found to be 1:4 (metal:ligand). The effect of diverse ions has been studied and the method was found to be applicable in the determination of bismuth from alloy samples.