The recent interest in germanium as an alternative channel material for PMOS has revealed major differences from silicon in relation to ion implantation. In this paper we describe some initial results of a fundamental study into defect creation and removal in ion implanted germanium. In this stage of the work we have used silicon and germanium implants into germanium and into germanium rich silicon-germanium. The defect evolution in these samples is compared with electron and neutron irradiated material using annealing studies in conjunction with deep level transient spectroscopy, positron annihilation and Rutherford back scattering. It is proposed that both vacancy and interstitial clustering are important mechanisms in implanted germanium and the likely significance of this is discussed.