The title compound, C19H15NO2S3, is the first example of a dithia analogue of pyrano[3,4-b]indolone. The almost planar thiopyranoindolethione ring system (r.m.s. deviation for all non-H atoms = 0.030 Å) makes a dihedral angle of 80.70 (8)° with the p-tolyl ring. In the crystal, molecules are connected via C—HO hydrogen bonds into two chains along the b axis. These chains are connected via π–π interactions between symmetry-related thiopyranoindolethione ring systems [centroid–centroid distance = 3.588 (1) Å].