10.22376/ijpbs.2019.10.1.p1-12 Volume 10 Issue 4 2019 (October-December) Oxovanadium (IV) complexes have been synthesized by reacting Oxovanadium (IV) sulphate with hydrazones derived from different aromatic (benzoic/4-chlorobenzoic/4-nitrobenzoic/4-methoxybenzoic/3-nitrobenzoic) acid hydrazides and 5-chloroisatin in ethanol in the presence of sodium acetate. All these complexes were characterized by elemental analyses, spectral techniques (UV-Vis, IR, and EPR) and magnetic moment measurements. The low molar conductance values indicate that they are non-electrolytes and the EPR spectra indicate that the free electron is in dxy orbital. A square pyramidal geometry is predicted for the synthesized complexes. lessThan i greaterThan In vitro lessThan /i greaterThan antibacterial activity was determined by screening the compounds against Gram-negative ( lessThan i greaterThan Escherichia coli lessThan /i greaterThan ) and Gram-positive lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan and lessThan i greaterThan Bacillus subtilis lessThan /i greaterThan ) bacterial strains and lessThan i greaterThan in vitro lessThan /i greaterThan antifungal activity was determined against fungi lessThan i greaterThan Aspergillus niger and lessThan /i greaterThan lessThan i greaterThan Candida albicans. lessThan /i greaterThan The oxovanadium (IV) complexes have a higher antimicrobial effect than free ligands. HARIKESH KUMAR, SHIVANI AND JITENDRA KUMAR PANDEY Oxovanadium (IV), 5-chloroisatin, IR, EPR, antimicrobial 75-82