The presented results are a continuation of our research on the synthesis and biological properties of halogen benzofuran derivatives, particularly their anticancer potential. We examined the cytotoxicity of two derivatives, methyl 4-chloro-6-(dichloroacetyl)-5-hydroxy-2-methyl-1-benzofuran-3-carboxylate (7) and methyl 6-(dibromoacetyl)-5-methoxy-2-methyl-1-benzofuran-3-carboxylate (8), in the following human cancer cell lines: SW480, SW620, HCT116, HepG2, PC3, A549, and MDA. The MTT assay results showed that compound 7 exhibited the most promising activity against A549 cells, while compound 8 demonstrated significant activity against both A549 cells and HepG2 cells. The biological activity of these compounds was evaluated by the trypan blue assay, reactive oxygen species generation, lipid peroxidation and IL-6 secretion. To investigate the proapoptotic activity of these compounds, the two following types of tests were performed: Annexin V Apoptosis Detection Kit I and Caspase-Glo 3/7 assay. Moreover, we checked the effect of both tested derivatives on the cell cycle and tubulin polymerization. The obtained results revealed that the presence of bromine and methoxy group in the structure has an influence on the biological properties of compound 8. This derivative exhibited stronger pro-oxidative effects and proapoptotic properties compared to those observed for derivative 7. Both compounds decreased IL 6 secretion in the tested cancer cell lines; however, the stronger effect was observed for HepG2 cells. Analysis of the cell cycle in the presence of the tested compounds revealed that compound 7 induced G2/M phase arrest in HepG2 cells, while compound 8 caused cell cycle arrest at the S and G2/M phases in A549 cells. On the other hand, both derivatives had a minimal effect on tubulin polymerization. These findings suggest that compounds 7 and 8 could serve as starting points for further development of anticancer agents.