The title compound, C19H23N3S, is a functionalized triazoline-3-thione derivative. The benzyl ring is almost normal to the planar 1,2,4-triazole ring (r.m.s. deviation = 0.007 A°) with a dihedral angle of 86.90 (7)°. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds, forming inversion dimers that enclose R2/2(8) loops. The crystal packing is further stabilized by weak C—H...n interactions that link adjacent dimeric units into supramolecular chains extending along the a-axis direction