Neutrino Masses, Baryogenesis and Bilinear R-parity Violation

We consider the impact of cosmological $B-L$ constraints on supersymmetric standard models with bilinear breaking of R-parity. In order to avoid erasing any primordial baryon or lepton asymmetry above the electroweak scale, $B-L$ violation for at least one generation should be sufficiently small. Working in the context of models with non--universal soft supersymmetry breaking masses, we show how the above cosmological constraint can be satisfied while simultaneously providing a neutrino mass matrix required by current data.