New formazan derivatives F-1 and F-2 were synthesized and tested as antioxidant and anticancer agents. Chemical structures of compounds were proved by spectroscopic methods (FT-IR, 1H-NMR and GC-Mass) and elemental analysis (CHN). The cytotoxicity activity of formazan derivatives was estimated against human breast cancer (MCF-7) cells. The synthesized compounds exhibited significant cytotoxic activity toward MCF-7 cell lines. Compound F-1 showed the highest toxicity toward MCF-7 cells. MTT assay demonstrated that 16 µg/ml of compound F-1 reduced cell growth by 88.33%, after 48 hours. Hemolysis study demonstrated that the hemolysis percentage of compounds F-1 and F-2 at (10 mg/ml) concentration was (4.05% to 4.18%), this result indicates the safety of their use inside the body. The antioxidant activity of the formazan compounds against DPPH radicals was tested in vitro. The results displayed that compound F-1 has stronger antioxidant activity than compound F-2. The new compounds were investigated in the gas phase using HyperChem software, applying semi-empirical methods and molecular mechanics. The heat of formation, binding energy, HOMO-LUMO, energy gab and dipole moment were calculated, and the results showed that compound F-1 was more stable and more polar than F-2.