Metal complexes of a novel tetradentate Nor-o-phdn.2H2O Schiff base were synthesised and characterised using the elemental analysis, mass spectrometry, 1H-NMR, FT-IR, electronic and thermal studies. The stoichiometry of the metal complexes was shown to be of carboxylic oxygen. UV absorption and magnetic susceptibility measurements indicated octahedral geometry for complexes. Thermodynamic's parameters were evaluated for the decomposition steps. In vitro antibacterial bioactivity of the Schiff base and its metal-derived complexes exhibited a strong inhibitory-bioactivity towards E. coli as well as S. typhi strains when compared with the parent ligand (Norfloxacin), while the metal complexes proved to be more active than Schiff base against S. aureus. With respect to B. cereus, only Ni (II) and Co (II) complexes were observed to possess a significant antibacterial bioactivity and can be clinically employed in the creation of new antibiotics. On the contrary, there is no evidence for a significant antifungal bioactivity against A. niger and P. vulpinum. Regarding the peculiarity of this work, the anti-huCMV effect of our synthetic compounds, using humanised-infected mice, was evaluated. Findings indicated that the Schiff base had no antiviral bioactivity; however, the complexation with Fe (III) and Zr (IV) metals was effective in reducing huCMV replication. Therefore, these two metal complexes hold a great promise in developing a potential antiviral treatment. Even so, further clinical studies on a large scale are required. 1:1 metal to ligand ratio, and all of the newly synthesised metal complexes were shown to possess electrolytic behaviour. The FT-IR spectral studies reveal that Nor-ophdn.2H2O has tetradentate chelated with the metal ions via two nitrogen of azomethine group and deprotonating