The crystal and molecular structure of di-2-pyridyl disulfide has been determined by single-crystal X-ray diffraction using the 1578 unique and significant (at the 3o level) reflections for which 20 < 50 °, and was refined to an unweighted R index of 0.048. Counter methods and monochromatized Mo Ka radiation were employed. Crystals form in the monoclinic space group P2~/c (or P2~) with cell dimensions a = 13.310 (3), b = 5.581 (2), c= 15.946 (5) A, and/~ = 119.55 (2) °. All H atoms were located on a difference Fourier function and their positions were refined. The S-S bond length is 2.016 (2) A and the average S-C distance is 1-785 A. The C-S-S-C torsion angle is 87.1 o. The S-S bond is nearly in the plane of each pyridine ring, one of which is disordered in P2~/c.