In the title mol-ecule, C(12)H(15)NS(2), the 1,3-thia-zinane ring has a half-boat conformation; the C atom at position 5 deviates by 0.715 (2) Å from the mean plane (P) of the remaining five atoms. Plane P and the phenyl ring form a dihedral angle of 83.62 (3)°. In the crystal structure, weak inter-molecular C-H⋯S hydrogen bonds link mol-ecules related by translation along the axis a into chains.