In the title compound, C28H22N2O8S, the carbazole ring system is roughly planar, with a maximum deviation of 0.084 (3) Å for the C atom connected to the 4,5-dimeth-oxy-2-nitro-phenyl ring. The dihedral angle between the carbazole system and the dimeth-oxy-substituted nitro-phenyl ring is 57.05 (10)°. The aldehyde C atom deviates by 0.164 (5) Å from its attached carbazole ring system. The mol-ecular structure is stabilized by C-H⋯O inter-actions which generate two S(6) and one S(7) ring motif. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming R 3 (3)(15) ring motifs, which are further crosslinked by R 3 (2)(19) ring motifs, resulting in (002) layers. The crystal packing also features C-H⋯π inter-actions.