Crystals of the title compound were obtained as a 1:1 dimethyl sulfoxide solvate, C(20)H(16)N(2)O(2)·C(2)H(6)O. The mol-ecular conformation of the organic mol-ecule is similar to that in the previously reported unsolvated structure [Eltayeb et al. (2009 ▶). Acta Cryst. E65, o1374-o1375]. Thus, the dihedral angles formed by the benzimidazole moiety with the two benzene rings are 57.54 (4) and 76.22 (5)°, and the dihedral angle between the benzene rings is 89.23 (5)°. In the crystal, a three-dimensional network features O-H⋯O, O-H⋯N and O-H⋯S hydrogen bonds, as well as C-H⋯O and C-H⋯π inter-actions.