Background: Cancer is a malignant disease characterized by the uncontrolled division of cells, leading to the invasion and destruction of healthy tissues. Copper(II) complexes of 1,10-phenanthroline and its derivatives have demonstrated various biological activities, including anti-tumor, anti-Candida, antimycobacterial, and antimicrobial effects. The aim of the study:To investigate the anti-proliferative effect of Cu(phen)(D-threo)NO₃+ F on the ovarian cancer cell line (A2780) and the colorectal cancer cell line (HT-29). Materials and methods: The copper compound was tested against A2780 and HT-29 cells using the MTT assay at concentrations of 1.0, 2.0, 5.0, 10, 15, and 20 µM, followed by incubation for 24, 48, and 72 hours. IC₅₀ values were determined to assess the compound’s potency. Subsequently, apoptosis induction was evaluated by quantifying caspase-9 protein expression using a human caspase-9 ELISA kit, and DNA fragmentation activity was assessed through agarose gel electrophoresis. Results: The MTT assay revealed that increasing concentrations of the copper compound led to a dose-dependent decrease in cell viability across all incubation periods for both cancer cell lines. The IC₅₀ value for A2780 cells was 1.70±0.26 µM after 72 hours, indicating greater sensitivity compared to HT-29 cells, which exhibited an IC₅₀ of 8.42±0.63 µM. Despite its cytotoxic effects, the compound did not induce apoptosis via the caspase-9 pathway, nor did it promote DNA fragmentation in either cell line, as no significant differences were observed compared to the control group in both assays. Conclusion: Cu(phen)(D-threo)NO₃ + F demonstrated a significant anti-proliferative effect on A2780 and HT-29 cancer cell lines, occurring independently of apoptotic pathways