The synthesis and the first X-ray structural characterization of a selenenyl selenocyanate, [o-(2,6-diisopropylphenyliminomethinyl)phenyl]selenenyl selenocyanate (), with a stable Se-Se bond are described. The isolation of stable , both in the solid state and in solution, is facilitated by strong intramolecular SeN interaction. The compound , an example of unsymmetrical diselenide, did not exhibit any glutathione peroxidase-like activity. The reaction of with thiophenol afforded (3H-benzo[c][1,2]diselenol-3-yl)(phenyl)sulfane.