Lepton flavour violating (LFV) decays of τ are an excellent place to search for physics beyond the Standard Model (SM). Both Babar and Belle have reached an experimental sensitivity of 10-7, the LFV level expected within many extensions of SM and SUSY. I will review Babar searches of LFV in τ decays including τ->l γ, τ->lll and τ->lhh (l=e,μ) and investigate the limits on SUSY parameters space set by these results in combination with other low energy observables such as measurements of cold dark matter density and of muon anomalous magnetic moment.