arXiv:hep-ph/0202122 v2 19 Cosmological implications of neutrinos are reviewed. The following sub-jects are discussed at a different level of scrutiny: cosmological limits on neu-trino mass, neutrinos and primordial nucleosynthesis, cosmological constraintson unstable neutrinos, lepton asymmetry of the universe, impact of neutrinoson cosmic microwave radiation, neutrinos and the large scale structure of theuniverse, neutrino oscillations in the early universe, baryo/lepto-genesis andneutrinos, neutrinos and high energy cosmic rays, and briefly some more ex-otic subjects: neutrino balls, mirror neutrinos, and neutrinos from large extradimensions.