Complexes of Schiff base were synthesized by direct condensation of acetaldehyde with thiosemicarbazide in the presence of FeCl3.6H2O and CuSO4.5H2O. The products were characterized by elemental analysis, molar conductance, infrared as well as electronic spectra study. The complexes are of 1:2 (metal:ligand) stoichiometry and are non-electrolytes in solution. On the basis of these spectra data, the general formulas: Cu(ADTSC)2SO4H2O and Fe(ADTSC)2Cl2.3H2O and an octahedral geometry was proposed for the complexes. The ligand and its complexes were screened for their antibacterial activities against Salmonella typhi, Shigella sp, Escherichia coli, Klebsiella sp, Staphylococcus aureus Pseudomonas aeruginosa and Vibrio cholera. The results of these studies showed that the metal complexes displayed more antibacterial activities against most of the species as compared to the uncomplexed ligand. The minimum inhibitory concentrations (MICs) of the compounds were also determined by two fold serial dilution method, the results showed an MIC value in the range of 500-250 µg/ml for the free ligand and 250-62.50 µg/ml range for the complexes. Results obtained from the toxicity effects of administration of the ligand and metal complexes at the doses of 25 and 50mg/kg body weight daily for 5 days showed that both doses of acetaldehyde thiosemicarbazone significantly increased (P<0.05) the levels of AST, ALT and ALP when compared to the control group, 50mg/kg body weight of acetaldehyde thiosemicarbazone copper(II) complex equally increased significantly(P< 0.05) the level of ALT based on comparison with the control group. The toxicities of other compounds were considerably non-significant (P≥ 0.05).