Lepton Number and Lepton Flavour Violation in Left-Right Symmetric Models

The sources of lepton flavour and lepton number violation in the left-right symmetric models are reviewed and the most sensitive processes to these violations are discussed. Both the non-SUSY and SUSY versions of the theories are considered. Present and future experimental constraints at low as well as at high energies are discussed. Some emphasis has been put on the doubly charged particle production at future colliders.