Many popular attempts to explain the observed patterns of fermion masses involve a flavon
field. Such weakly coupled scalar fields tend to dominate the energy density of the Universe
before they decay. If the flavon decay happens close to the electroweak transition, the right-
handed electrons stay out of equilibrium until the sphalerons shut off. We show that an
asymmetry in the right-handed charged leptons produced in the decay of a flavon can
explain the baryon asymmetry of the Universe.