Ion pairing may have a strong influence on the kinetics and mechanisms of electrochemical reactions as reflected by the location of the corresponding half-wave (or peak) potential. Upon increasing the extent of ion pairing (by increasing the binding constant and/or the concentration of associating ion), the following changes are expected, taking a reductive formation of the ion pair as example. For moderate ion pairing and fast electron transfer, a positive shift of the reversible half-wave (or peak) potential by 59.6 mV (at 25 degreesC) per 10-fold increase of the associating ion concentration is predicted. Next, fast and strong ion pairing prompts the forward electron transfer to become rate determining. On the oxidation side, a predissociation mechanism, involving a positive shift of the wave, prevails as long as the extent of ion pairing is not too large. Upon increasing the extent of ion pairing, the height of the predissociation wave rapidly drops to zero. Direct electron transfer to the ion pair, associated with the expulsion of the associating ion, then takes place according to a mechanism in which the breaking of the ion-pair bond is successive to or concerted with electron transfer. In the latter case, the applicability of the dissociative electron-transfer theory previously developed for reductive cleavages is discussed based on appropriate quantum chemical computations.