In the title compound, C21H17N3O4, pairs of molecules form a planar[maximum deviation 0.0566 (9) Å] centrosymmetric imidazole dimer via two N—H⋯O hydrogen bonds. These dimeric units are linked by further N—H⋯O hydrogen bonds between the ester carbonyl group and the imidazolidine ring, formiing chains parallel to the c-axis direction. In addition, there are π–π stacking interactions between the planar imidazole pairs, with an interplanar spacing of 3.301 (2) Å. There is a double bond with Z geometry connecting the imidazolidine and indole units