X-ray powder diffraction data, unit-cell parameters, and space group for methylene bis(thiocyanate) (C3H2N2S2) are reported [a = 6.6888(4) Å, b = 8.0616(6) Å, c = 11.089(1) Å, β = 105.33(1), Z = 4, unit-cell volume V = 576.68(7) Å3, with M20 = 56.0 and F30 = 43.8 (0.0079, 87)]. All measured lines were indexed and are consistent with the monoclinic I2/c space group.