A new series of Co(II), Ni(II), Cu(II) and Zn(II) complexes with a Schiff base derived from 4-amino-3-mercapto-5-oxo-1,2,4-triazine and 2,4-dichlorobenzaldehyde have been synthesized and characterized by spectroscopic studies. The coordination possibility of the Schiff base towards the metal ions have been determined by analytical, spectral (IR, 1H NMR, electronic spectroscopy, fluorescence, ESR) and thermal techniques. IR and thermal data support the presence of coordinated water in the metal complexes. The low molar conductance values in DMF indicate the non-electrolytic nature of the metal complexes. All the synthesized metal complexes show enhancement in fluorescence intensity in comparison to the ligand. The cyclic voltammetric studies of the Co(II), Ni(II) and Cu(II) complexes suggested the single electron transfer quasi-reversible nature of the complexes. Antimicrobial studies of the ligand and its metal complexes have been carried out in vitro against gram positive (S. aureus, B. subtilis), gram negative bacteria (E. coli, P. aeruginosa) and yeasts (S. cerevisiae, C. albicans).