In the title compound, C(15)H(14)N(4)O(2)S·0.4C(3)H(6)O·0.1CH(2)Cl(2), two benzene rings in the ortho-meth-oxy dehydro-dithizone (omd) mol-ecule are twisted out of the tetra-zole plane with the meth-oxy groups in a cis orientation relative to the tetrazole backbone. The acetone is located on a special position. The dihedral angles formed by the benzene rings with the central five-membered ring are 63.14 (8) and 57.06 (6)°. In the crystal structure, the relatively short distance of 3.886 (3) Å between the centroids of benzene rings from two neighbouring omd mol-ecules indicate π-π stacking inter-actions.