We have searched for τ lepton decays, τ-→Λ̄π- and τ-→Λπ-, that simultaneously violate the conservation of the lepton (L) and baryon (B) number using a data sample of 154 fb-1 collected with the Belle detector at the KEKB e+e- asymmetric-energy collider. No evidence for a signal was found in either of the decay modes and we set the following upper limits for the branching fractions: B(τ-→Λ̄π-)