We consider the Chevalley involution in the context of real reductive groups.
We show that if G(R) is the real points of a connected reductive group, there
is an involution, unique up to conjugacy by G(R), taking any semisimple element
to a conjugate of its inverse. As applications we give a condition for every
irreducible representation of G(R) to be self-dual, and to the Frobenius Schur
indicator for such groups