The NA62 experiment at CERN SPS aims to measure the branching ratio of the ultra-rare kaon decay $K^+\to\pi^+\nu\bar{nu}$ with 10\% precision, collecting $\sim 100$ events, assuming the Standard Model~(SM) branching ratio of $8.4 \times 10^{-11}$, starting in 2016.
The NA62 experiment uses a kaon decay-in-flight technique and is exposed to a 750~MHz high-energy unseparated charged hadron beam, in which kaons are a minor component (6\%). Kaon identification is therefore mandatory to reduce the interference of the dominant non-kaon component with the experimental measurements. The NA62 kaon identification system and its performances are presented.