  We discuss leptogenesis in the light of indications of neutrino masses and
mixings from Super-Kamiokande and other data on atmospheric neutrinos, as well
as the solar neutrino deficit. Neutrino masses and mixings consistent with
these data may produce in a natural and generic way a lepton asymmetry that is
suffient to provide the observed baryon asymmetry, after processing via
non-perturbative electroweak effects. We illustrate this discussion in the
framework of the string-derived flipped SU(5) model, using particle assignments
and choices of vacuum parameters that are known to give realistic masses to
quarks and charged leptons. We display one scenario for neutrino masses that
also accommodates leptogenesis.
