  The effects of large CP violating phases arising from the soft SUSY breaking
parameters on the proton lifetime are investigated in supersymmetric grand
unified models. It is found that the CP violating phases can reduce as well as
enhance the proton lifetime depending on the part of the parameter space one is
in. Modifications of the proton lifetime by as much as a factor of 2 due to the
effects of the CP violating phases are seen. The largest effects arise for the
lightest sparticle spectrum in the dressing loop integrals and the effects
decrease with the increasing scale of the sparticle masses. An analysis of the
uncertainties in the determination of the proton life time due to uncertainties
in the quark masses and in the other input data is also given. These results
are of import in the precision predictions of the proton lifetime in
supersymmetric unification both in GUT and in string models when the soft SUSY
breaking parameters are complex.
