A selected survey of the formation and properties of a number of sulfur- and selenium-centered radical ions is presented. The focus is on radical cations in which two heteroatoms are linked by a bond containing a total of three electrons, namely two bonding s-electrons and one antibonding s*-electron. Examples are (R₂S\SR₂)⁺ and (R₂Se\SeR₂)⁺ derived from simple aliphatic sulfides and selenides, and corresponding species in which the heteroatom coupling occurs intramolecularly. It will be demonstrated how structure and substituents influence the thermodynamic and kinetic stability of such systems. Owing to the strong and distinct optical absorptions in the ultraviolet (UV) and visible all of these species may conveniently be detected by means of time-resolved optical spectroscopy, especially pulse radiolysis. These and complementary data obtained from mass spectrometry and electrochemistry will be presented and discussed.