In the mol-ecule of the title compound, C(18)H(12)N(2)OS, the tetra-hydro-benzo[h]quinoline fused-ring system is buckled owing to the ethyl-ene -CH(2)CH(2)- fragment, the benzene ring and the pyridine ring being twisted by 16.0 (1)°. The 4-substituted aromatic ring is bent away from the pyridine ring by 59.5 (2)° (for the major disordered thienyl component) in order to avoid crowding the cyanide substituent. In the crystal, two mol-ecules are linked by a pair of N-H⋯O hydrogen bonds to form a centrosymmetric dimer. The thienyl ring is disordered over two sites in a 72.7 (2):27.3 ratio.