Three 1,3-disubstituted benzimidazolium salts (3a-c) were efficiently synthesized in moderate to high yields (52–83 %) and analyzed through NMR spectra. The anti-cancer efficiency of these compounds was tested on human liver cancer (HepG2), lung cancer (A549), and normal embryonic kidney (HEK-293T) cell lines. The results demonstrated that compound 3b emerges as a promising candidate for further investigation due to its high cytotoxicity, comparable to cisplatin. The optimized geometry, electronic properties, chemical parameters and frontier molecular orbitals of 3a-c were determined by DFT calculation using density functional theory (DFT) with the B3LYP/6–31++G(d,p) level in the ground state. In addition to the experimental studies, compounds 3a-c were docked against target protein PDB ID: 6V9C representing the HepG2 cell line.