Some selected transition (Cu II , Cr III , Mn II , Fe III , Co II and Ni II ) and non-transition (Zn II and Pb II ) metal complexes of arylhydrazones, namely o-hydroxyacetophenone benzoy lhydrazone (HBH) and o-mthoxybenzaldehyde benzoylhydrazone (MBH) have been isolated and char acterized by a combination of elemental analysis, s pectral (UV-Vis., IR, 1 H NMR) and magnetic measurements. Only two divalent metals (Cu II and Ni II ) yield stable complexes with MBH. The mode of bonding as well as the geomet ry of the solid complexes was identified. The resul ts and discussion pointed out that HBH and MBH coordinate to the central metal ion in a bi and/or tridentate manner with forming a dimeric structures in case of Cu II , Fe III , Ni II , Zn II and Pb II -HBH while a classic mononuclear structures in case of (Cu II , Ni II -MBH) and (Cr III , Mn II -HBH) complexes. The amount of solvent inside and o utside the coordination sphere of solid samples was determined by the aide of thermal measurements. The prepared ligands and their metal complexes have been evaluated for t heir antimicrobial activity against Gram-positive a nd Gram- negative bacteria as well as for antifungal activit y. The metal complexes were much more active than t he original compound. In addition, the complex Ni II -HBH showed the highest both antifungal and antibac terial activities against all microbial tested whilst the compound M BH revealed the lowest