A novel azo schiff base dye (L) have been Synthesized a reaction of 5-[ 2-(5-nitro thiazolyl)azo] -2-amino -4-methyl pyridine (NTAPy) with 4-chloro benzaldehyde in alkaline solution . Anew series of complexes with Ag(I), Au(III) and Pt(IV) ions were Prepared forming chelate complexes. The structure of azo schiff base ligand and its metal complexes were characterize by different spectral technique such as 1 H-NMR, 13 C-NMR, mass spectrum, FT-IR, electronic spectra, C-H.N.S analysis, maganetic susceptibility, atomic absorpotion and molar conductivity. The analytical data suggest the mole ratio [ M:L] was [l:l] for Ag(I) and Au(III) ions but [l:2] for Pt(IV) ion. The metal complexes of Au(III) and Pt (IV) was l:l and l:2 electrolyte receptivity while the Ag(I) complex is non electrolyte . In this study the cytoxicity of Ag(I), Au(III), and Pt (IV) complexes on human (PC3) breast cancer and normal cells were MTT assay. The metal complexes showed selective cytotoxicit against breast cancer , this metal Complexes excelled in halting proliferation of PC3 cancer cells with median inhibitory concentration (lC50) values of Mg/ml , µg/ml and µg/ml for Ag(I),Au(III) and Pt(IV) complexes. The results indicate undoubtedly the possibility of using them as antitumor drugs in the field of pharmacy breast cancer.