In this study, Cr (III) and Fe (III) complexes were synthesized in the presence of p-Brom-2,6-bis(hydroxymetyl)phenol (L1), nicotinamide (L2), and diethylenetriamine (L3) under refluxing conditions. The chemical structures of the synthesized complexes were characterized using ESI-MS, UV-Visible, IR, TG-DTA. Optimization of the reactions to obtain the composition of complexes were determined using UV-Visible, Molar Ratio and Job methods. Comparisons of the spectral measurements of ligands with those of the metal complexes are useful in determining the atoms of the ligand that will be coordinated to the metal ion. Additionally, the ligands and complexes displayed effective antioxidant activity. Antimicrobial properties of complexes were investigated by using Escherichia coli, Staphylococcus aureus, Salmonella thyphimirium, Listeria monocytogenes and Candida albicans microorganisms and were observed to be active against these microorganisms. Also, these four complexes were seen to be effective on human breast (MCF 7) and prostate (Du145) cancer cells.