Lepton Flavour Violation: present and future Experiments

Lepton flavour violating effects are predicted in many supersymmetric extensions of the Standard Model at a measurable level. Since the Standard Model background is completely negligible, the observation of such effects would be a strong evidence for physics beyond the Standard Model and for the supersymmetric frame. In this talk I review the present status of the lepton flavour violation experiments involving muons and tau's and discuss the sensitivity improvements which can be expected from future high intensity accelerators.