The HARP experiment, at the CERN Proton Synchrotron, measures hadron production cross sections of protons of well known momenta (2 – 15 GeV/c) impinging on various solid and liquid targets. Precise pion yield measurements, for neutrino factory studies and atmospheric neutrino experiments have been completed over almost the full solid angle. The HARP Time Projection Chamber which is part of the large angle spectrometer, provides tracking and particle identification of secondaries with transverse momenta down to 20 MeV/c and at angles comprised between 10° and 160°. Built in a record time of less than 1.5 years its small size called for innovative solutions in order to conserve the maximum active detection volume. A short description of the HARP Time Projection Chamber, which operated successfully from August 2001, will be given in the following document. Preliminary results regarding track reconstruction and momentum resolution are also given.