The Nickel (II) metal complexes have been prepared by treating nickel sulphate with different newly prepared ligands. The preparation of ligands with various aldehydes such as anisaldehyde, benzaldehyde, p-nitrobenzaldehyde, α-naphthaldehyde and p-methylbenzaldehyde. The present ligands and metal complexes have been characterised by elemental analysis and various physicochemical techniques such as Electronic absorption, Molar conductance, Magnetic susceptibility, Infrared spectral studies and Thermal analysis. The results of various physicochemical techniques discussed in detail and the possible structures are proposed to the reagents and complexes. The newly synthesized complexes have been screened for their antibacterial and antifungal effects against the number of gram positive and gram negative bacteria and different fungi.