The first isolable 'side-on' supersulfidonickel(II) complex 1(1) with the elusive S2(-center dot) ligand has been synthesized by facile oxidation of the corresponding nickel(I) precursor [LNi] with elemental sulfur. Remarkably, paramagnetic 1(1) associates voluntarily to give the diamagnetic dimer 1(2) with a four-sulfur two-electron bond as proven by X-ray diffraction analysis, spectroscopic measurements (H-1 NMR, EPR, SQUID), and DFT calculations. Gentle sulfur transfer of 1(1) to Ph3P or its reaction with [LNi] affords solely the genuine disuffide complex 3 having a Ni-2(mu-mu(2):mu(2)-S-2) core.