Antimicrobial activity of 2-(2-hydroxyphenyl)-5-R5-1H-benzimidazoles, 2-(2-hydroxy-5-R5'-phenyl)-1H-benzimidazoles and their FeIII, CuII, AgI, ZnII and HgII nitrate complexes was tested toward Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, and Proteus mirabilis. Antifungal activity was tested against Candida albicans. Benzimidazole benzene ring substituents increase the antimicrobial activity, phenol ring substituents decrease it. The ligands show an antibacterial effect against only S. aureus whereas AgI and HgII complexes of the ligands have a higher activity with respect to the other complexes to all the bacteria. On the other hand, FeIII complexes show a considerable activity against S. aureus and S. epidermidis.