Bounds on Broken R-Parity from NOMAD and CHORUS

We determine new constraints on the products of two R-parity violating coupling constants from the NOMAD and CHORUS experiments on nu_mu --> nu_tau oscillations. We obtain improved results from (a) lepton flavour violating (LFV) meson decays, (b) LFV deep-inelastic scattering and © a combination of the two.