The quantity ε'/ ε measures direct CP violation in Kaon decays. Recent analysis of this ratio did result in a 2.9 sigma discrepancy between the Standard Model predictions and the experimental data. Our ability to observe or constrain New Physics depends on the accuracy of determining the SM ”background”, so precise evaluation of ε'/ ε in this framework is particularly important. In this talk I will discuss the Standard Model prediction and the relevant matching calculations at NNLO.