In the present study, we synthesized novel benzimidazole-silver(I) complexes (2a-d) by the interaction of 1-benzyl-3H-benzimidazolium p-toluenesulfonate derivatives (1a-d) and Ag2O in order to investigate their anticancer properties. All the salts and complexes were fully characterized by H-1 NMR, C-13 NMR, IR and LC-MS spectroscopic techniques, elemental analysis and single crystal X-ray crystallography. Cytotoxic effects of compounds were investigated by MTT test against human colorectal (Caco-2), breast (MCF-7) cancer cell lines and non cancer mouse fibroblast (L-929) cell lines. All the complexes performed more cytotoxicity than cisplatin against Caco-2 cell lines while they were not active against MCF-7 in the treatment concentrations. Among the complexes, 2d which contains chlorine at 2-position of benzyl was found out as most active but not selective for non cancer L-929 cell lines. The complex 2b which contains methyl instead of chlorine at 2d showed approximately equal cytotoxicity as cisplatin against L-929 cell lines while this complex was twofold active than cisplatin against Caco-2 cell lines. These findings suggest that complex 2b is a promising candidate for treatment of colorectal cancer. (C) 2018 Elsevier Ltd. All rights reserved.