In the title compound, C(20)H(13)N(3)S, the partially saturated ring adopts a twisted half-boat conformation with the methyl-ene C atom closest to the amino-benzene ring lying 0.690 (6) Å out of the plane defined by the five remaining atoms. The dihydro-phenanthrene residue has a folded conformation [dihedral angle between the outer benzene rings = 26.27 (18)°]. The thio-phen-2-yl ring forms a dihedral angle of 63.76 (19)° with the benzene ring to which it is attached. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R(2) (2)(12) loops. The dimers are linked into layers in the bc plane by weak C-H⋯π inter-actions. The thio-phen-2-yl ring is disordered over two essentially coplanar but opposite orientations in a 0.918 (4):0.082 (4) ratio.