The Schiff base formed from the reaction of hydrazine and 2-hydroxyacetophenone was synthesized and investigated by using several physical techniques, in particular; CHN elemental analysis, infrared, ultraviolet and mass spectra. Only one product was formed from the reaction of the carbonyl and primary amine. The purity of the isolated Schiff base was confirmed by its melting points and by TLC technique. The Schiff base under investiga-tion forms complexes with Co(II), Ni(II), Cu(II), Cr(III) and La(III) ions. The synthesized complexes were con-firmed by elemental analysis, molar conductivity, thermogravimetric analysis (TGA)analysis and spectral (IR, elec-tronic and ESR) measurements. The analytical data show the formationof 1:1 (M:L) complexes. The molar con-ductance measurements of the complexes reveal a non-electrolytic nature. The thermogravimetric analysis data of some complexes show the presence of coordinated and hydrated molecules water. The infrared spectral data display the chelation behavior of the Schiff base towards the metal ions. The electronic spectral results of the Schiff base and its complexes show π→π* (phenyl ring), n→π* (HC=N) and the expected geometrical structures for the synthesized complexes. Basis on the electron paramagnetic resonance spectral data, an octahedral structure was suggested for all complexes. The synthesized Schiff base and its complexes were tested against some pathogenic bacteria [Esche-richia coli,ProteusSp, Pseudomonas aeruginosaand Staphylococcusaureus].