  We present a new calculation of the CP violation parameter
$\epsilon^{\prime}/ \epsilon$. The results reported in this paper have been
obtained by using the $\Delta S=1$ effective Hamiltonian computed at the
next-to-leading order, including QCD and QED penguins. The matrix elements of
the relevant operators have been taken from lattice QCD, at a scale $\mu=2$
GeV. At this relatively large scale, the perturbative matching between the
relevant operators and the corresponding coefficients is quite reliable.
  The effect of the next-to-leading corrections is to lower the prediction
obtained at the leading order, thus favouring the experimental result of E731.
We analyze different contributions to the final result and compare the leading
and next-to-leading cases.
