Two complexes of Fe(II) with 1,10-phenanthroline (phen) and its Ph(2) derivative (bphen) ([Fe(phen)(3)](2)[FeCl(4)]Cl(2)center dot 5H(2)O and (Fe(bphen)(3)](2)[FeCl(4)]Cl(2)center dot 5H(2)O), resp., were synthesized, characterized by UV, IR and NMR spectroscopies and studied for cytotoxic activity against human cancer cell lines and against some strains of bacteria and fungi. The complexes showed an interaction with plasmid and genome DNA and a strong antitumor activity. The bphen complex was effective as an antibacterial agent against Gram-pos. bacteria.