2-(5- bromo-2- oxoindolin-3-ylidene) hydrazine carbothioamide,[5-Bromoisatin thiosemicarbazone (HBITSC)] extracts Iridium (III) quantitatively (99.79%) into n-amyl alcohol. The n-amyl alcohol extract shows an intense peak at 500nm (λ max). Beer’s law is obeyed over the Ir(III) concentration range 1.0 – 6.0ug/ml. The molar absorptivity is 1153.35 L mole-1cm-1 at 500 nm and Sandel’s sensitivity is 16.66 ng/cm2. The composition of extracted species found to be 1:3 (Ir: HBITSC) by Job’s continuous variation and Mole ratio method. Interference by various ions has been studied. The proposed method has been applied for the determination of Ir (III) in synthetic sample.