Synthesis and investigation of new Co(II), Ni(II), Cu(II), Zn(II) and Cr(III)chelates of mixed ligands including aSchiff base [(E)-2-(4-(dimethylamino)benzylideneamino)phenol] (C15H16N2O) derived from the condensation of 4- dimethylaminobenzaldehyde with 2-aminophenol as main ligand (L1) and an amino acid; L-Histidine as co-ligand (L2) were studied. The obtained Schiff base and the mixed ligand chelates were subjected to several physiochemical techniques, in terms of CHN elemental analyses, molar conductivity, magnetic moment measurements, infrared, electronic and mass spectroscopies. The CHN analytical data showed the formation of the Schiff base compound and the mixed ligand chelates in 1:1:1[M:L1:L2] ratio. All the prepared mixed ligand chelates were non-electrolyte in nature. The infrared spectral data exhibited that the used ligands behaving as bidentate ligands towards the metal ions. The 1HNMR spectra of the ligands and their Zn(II) mixed ligand chelate exhibited the effect of the activated groups of the ligands by the metal ion. The electronic spectral results showed the existence of π→π* (phenyl ring) and n→π*(HC=N) and suggested the geometrical structures of the chelates. Meanwhile, the mass spectral data revealed the fragmentations of the Schiff base, Histidine and their Cu(II) mixed ligand chelate. The studies made on these chelates proposed a six coordinated octahedral geometry for all these chelates. The antibacterial activities of the Schiff base, Histidine, metal salts and mixed ligand chelates were screened. It is found that the mixed ligand chelates have the most biological activity in comparison to the free ligands and salts.