  The measurement of epsilon'/epsilon has left open several theoretical
problems, the most important of which is an accurate calculation of the
relevant hadronic matrix elements. Here we study the possibility of relating
epsilon' to CP violation in charged K-> 3 pi, which can provide information on
the reliability of such calculations. We discuss the role of final state
interactions and the main sources of uncertainties. We find that the
measurement of Delta g_C in K-> 3 pi is a crucial consistency test for the
Standard Model calculations of epsilon'. Valuable information can be deduced
also from other observables.
