The crystal and molecular structure of di-tert-adamantyl disulfide (1, DAD; C20H30S2) has been determined from diffractometer data. The unit cell is monoclinic: space group P21/c; a = 12.015 (3), b = 11.556 (3), c = 12.959 (3) Å; β = 90.42 (2)°; V = 1799 Å3; Z = 4; = 1.24 Mg/m-3. Least-squares refinements gave R = 0.074 for 649 observed reflections. The torsion angle θ(CSSC) = 110.5 (9)°. The observation of an enlarged S-S dihedral angle permits a tentative extension of the correlation between 0(CSSC) and the photoelectron spectroscopically determined ionization energy difference, ∆E(n+-n-), and disulfide torsional angles above 90°. The molecular geometry of t-Bu-SS-t-Bu is revised accordingly.