Crystals of S4(NCH3)4 are orthorhombic, a = 25.483(6), b = 15.842(3), c = 5.642(2) Å, Z = 8, space group Fdd2, required molecular symmetry C2.•The structure was determined with CuKα diffractometer data by Patterson and Fourier methods, and refined by full-matrix least-squares methods to R = 0.067 for 473 observed reflexions. The eight-membered ring has a crown conformation, with approximate C4v symmetry, and the bonds at each nitrogen atom are slightly but significantly non-planar. Mean bond lengths are S—N = 1.677(4), C—N = 1.479(7) Å.