A series of Cu(II), Fe(III), Pb(II), Mn(II) metals complexes have been synthesized with the new thiazole azo dye containing tridentate [N.N.O] donor ligand 2-[2− -(5-nitro thiazolyl) azo]-4-methyl-5-nitro phenol (5-NTAMNP) derived from 2-amino-5-nitrothiazole and 3-methyl-4-nitrophenol by the diazotization operation and the adizonium chloride salt solution of 2-amino-5-nitrothiazole reacting with 3-methyl-4-nitrophenol as a coupling compound in alkaline alcoholic solution. The structures of synthesized novel ligand was identified and confirmed via resorting to various spectroscopic techniques which included, 1H NMR, Mass spectrum, UV–visible, Fourier-transform infrared (FTIR), X-Rays diffraction (XRD), the surface nature and morphology and size average and elemental composition of individual ligand particles were examined using a field emission scanning electron microscope (FESEM) coupled with an energy dispersive X-ray system (EDX), in addition to above the physical properties of ligand have been studied via check its melting point and the purity of the ligand also was checked by TLC in presence of a certain solvent system. As for the consistency positions available in (5-NTAMNP) and the manner of its association with these metallic ions it’s likely that the pattern of complexity as a tridentate chelating agent with the formation of a coordination number for all metallic ions found equal to six and have Octahedral shape for all metallic ion. The optimal condition for complexation have been studied, the prepared metallic complexes were identified via UV–visible & FT-IR spectra. All metallic complex and (5-NTAMNP) ligand were screened for their biological activities.