In vitro effect of two dinuclear and mononuclear iron complexes with different ligands was examined on Gram positive and Gram negative bacterial strains. Broad spectrum antibiotic oxytetracycline was used as control. The experiment was performed by the routine agar-diffusion method of bauer et al. and the method of  minimum inhibitory concentrations (MICs). It was found  that mononuclear complexes expressed antibacterial effect in vitro, especially against Gram (+) strains. The minimum inhibitory effect of Fe (NADP) Cl2 was more pronounced
