Abstract. The phenomenological models based on compactifications of the heterotic string are endowed with several symmetries, among which there are non-Abelian discrete groups that may be interpreted as flavor symmetries. Delta(54) is the largest discrete subgroup of SU(3) that may explain the number of generations in particle physics. In this talk, we discuss how orbifold compactifications generate naturally this symmetry and impose constraints that result in phenomenological simplifications. The consequences for flavor physics, besides adequate masses for quarks and leptons, include normal hierarchy and experimentally-favored values for mixing angles in the neutrino sector.