Some new nano-sized Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Cd(II), Zn(II),, Pb(II) and Ag(I) complexes with imine ligands derived from 2-amino-3-hydroxypyridine (ahp) and 3-methoxysalicylaldehyde (v) or 4-nitrobenzaldehyde (nb) were prepared by sonochemical method. Melting point, decomposition temperature, infrared (IR) and NMR spectra, elemental analyses, conductance and magnetic susceptibility measurements, TG and UV – Visible spectrophotometric studies were utilized in characterizing of the prepared imine ligands and their complexes. Also, DFT calculations were used to confirm the structure of the prepared compounds. The total energy of HOMO and LUMO, Mullikan atomic charges, dipole moment and orientation have been performed and discussed. Thermogravimetric (TG) analysis data indicated that the high thermal stability of all the prepared complexes and suggested the presence of lattice and/or coordinated water molecules in the complexes. Coats–Redfern method has been used to calculate the kinetic and thermodynamic parameters of the metal complexes. The molar conductance of prepared complexes in ethanol lies in the range 2.38- 23.7 Ω-1 cm2 mol-1, indicating their non-electrolytic nature. Moreover, the stoichiometry of the prepared complexes were determined spectrophotometrically. The curves of the continuous variation method indicate that the formation of complexes with metal ion to ligand ratio is 1:1 in case of ahpv complexes and 1:2 in case of ahpnb complexes (except ahpnbAg has stoichiometry 1:1). The pH profile revealed that the wide range of pH stability of the investigated complexes is at pH = 4- 11 in most of them. From the obtained data, ahpv ligand behaves as dibasic tridentate ONO ligand (except in case of Ag(I) complex which behaves as monobasic tridentate) and coordinates with metal ions in octahedral geometry in case of ahpvCo, ahpvNi, ahpvFe, ahpvCd and ahpvMn complexes and in tetrahedral geometry in case of ahpvCu, ahpvZn, ahpvPb and ahpvAg complexes. The general formulas of the complexes are [M(ahpv)(H2O)m].nH2O, where m is number of coordinated water molecules and n is number of hydrated water molecules. On the other hand, ahpnb ligand behaves as monobasic bidentate ON ligand and coordinates with metal ions in octahedral geometry for ahpnbCu, ahpnbCo, ahpnbNi, ahpnbFe, ahpnbCd and ahpnbMn complexes according to the general formula [M(ahpnb)2(H2O)2].nH2O and in tetrahedral geometry for ahpnbAg complex according to the general formula [M(ahpnb)(H2O)2].H2O. In addition, the prepared complexes were employed as precursors for synthesis of their corresponding metal or metal oxide nanoparticles by controlled aerobic thermal decomposition at 500oC. The structure, morphology and size of the prepared metal oxides were characterized by Fourier Transform Infrared Spectroscopy, X-ray powder diffraction, scanning and transmittance electron microscopy, respectively. The imine ligands, their complexes and their corresponding metal oxides were screened for their in vitro antibacterial activity against three bacteria, gram-positive (Microccus luteus) and gram-negative (Escherichia coli, Serratia marcescence) and three strains of fungus (Aspergillus flavus, Getrichm candidum and Fusarium oxysporum). The metal chelates were shown to possess more antimicrobial activity than the free imine ligands and their nano-sized metal oxides have the highest activity. Moreover, the binding behaviors of the prepared complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and gel electrophoresis. The obtained results reveal that all these complexes interact with DNA mainly through intercalative and replacement binding mode. Also the cytotoxic activity of the prepared imine ligands and their complexes on human colon carcinoma cells (HCT-116 cell line), Breast carcinoma cells (MCF-7 cell line) and hepatic cellular carcinoma cells (HepG-2) were tested and showed potent cytotoxicity effect against growth of carcinoma cells compared to the clinically used Vinblastine standard.