We investigate 'High Scale mixing unification' hypothesis in the context of Dirac neutrinos. This hypothesis assumes the unification of the mixing angles and phases of the CKM and PMNS matrices at some high scale. This could be a possible signature of the quark-lepton unification. After taking quarks mixing angles and Dirac phase equal to that of PMNS matrix, we run down renormalization-group equations of the neutrinos to the low scale. We observe that all the low-energy oscillation parameters are recovered.