A series of mononuclear Schiff base transition metal complexes of the type [ML1L2] (where, M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ; L1= Schiff base ligand derived from o-hydroxyacetophenone and L-cysteine; L2 = ethylenediamine) have been synthesized and characterized on the basis of elemental analysis, molar conductance and spectroscopic studies such as UV-Visible, FTIR and EPR. A square pyramidal geometry has been assigned based on the analyses. All the synthesized complexes and the Schiff base ligand were screened for their in vitro antibacterial against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli and antifungal activities against Aspergillus niger, Aspergillus flavus and Penicillium notatum by well diffusion method. In addition, the antioxidant and larvicidal activities were also done for all the metal complexes. The percentage of antioxidant scavenging activity and mortality of the larvicidal activity were also determined