In the present work, six new cobalt(II) complexes (1-6) of (E)-2-(2-hydroxy-3-methoxybenzylidene)-N⁴-methylhydrazinecarbothioamide (HL₁), (E)-2-(2-hydroxy-3-methoxybenzylidene)-hydrazinecarbothioamide (HL₂) and (E)-2-(2-hydroxy-3-methoxybenzylidene)-hydrazinecarboxamide (HL₃), have been synthesized and characterized. The FT-IR spectral data suggested the attachment of cobalt(II) ion to the Schiff’s base ligand moiety through the azomethine nitrogen, thioketonic sulfur and phenolic-O atom. The synthesized complexes 1-6 were tested for their antibacterial activities against two gram-positive bacteria (Bacillus subtilis and Escherichia coli) and two gram-negative bacteria (Pseudomonas aeruginosa and Staphylococcus aureus) and also screened for their antifungal activity against Aspergillus Niger and Candida Albicans. These complexes showed moderate to considerable effect on bacteria strains, whereas they showed moderate effect on fungal strains.