In the title compound, C(20)H(18)N(2)O(3), the C=C bond of the acrylonitrile group that links the indole and the 3,4,5-trimeth-oxy-phenyl rings has Z geometry, with dihedral angles between the plane of the acrylonitrile unit and the planes of the benzene and indole ring systems of 21.96 (5) and 38.94 (7)°, respectively. The acrylonitrile group is planar (r.m.s. deviation from planarity = 0.037 Å). Mol-ecules are linked into head-to-tail chains that propagate along the b-axis direction by bifurcated N-H⋯O inter-molecular hydrogen bonds, which form an R(1) (2)(5) motif between the indole NH group and the two meth-oxy O atoms furthest from the nitrile group.