Two new Cu (II) complexes [Cu (bpy)2L1] BF4.CH3OH (Z3) and [Cu (phen)2L1] BF4H2O (Z9), L1 = 5-Fluorouracil-1-yl Acetic Acid, were synthesized based on 5-Fluorouracil-1-yl Acetic Acid and 2,20-Bipyridine or 1,10-phenanthroline ligands and their anticancer activity toward human cancer cell lines investigated. The complexes were characterized by infrared (IR) spectra, elemental analysis, and X-ray crystallography. The interaction of the complexes with CT-DNA was investigated by UV–vis absorption and fluorescence spectroscopies, and cyclic voltammetry; cell viability (%) was studied using the absorbance amount of the samples. The interaction mode of the complexes with DNA is electrostatic, and the complexes displayed good anticancer activity against HCT 116 (human colorectal cancer cells) and MDAMB- 231 (MD Anderson-metastatic breast) cell lines with best IC50 amount of 11.31 ± 0.74 μM for Z9. The results showed that the nature of the nitrogendonor ligand is very effective in the anticancer activity of the complexes.