The silicon microstrip Tracker is a key subdetector of the AMS-02 instrument, designed to measure the momentum and charge of cosmic rays. The subdetector is composed of 9 layers of silicons sensors inside a permanent 0.15 T magnetic field. The detector has been installed on board of the International Space Station, at an altitude of 400 km, and is taking data since May 19th 2011. AMS-02 aims to provide a precise measurement of the cosmic-ray spectrum and perform antimatter searches in the GeV-TeV energy range. This review presents the Tracker performances during the first year of operation in space, covering all the most relevant aspects of detector stability, efficiency and capabilities in charge and track reconstruction.