The diffusion coefficient of copper in amorphous germanium is estimated to be larger than 3 x 10(-11) cm(2) s(-1) and the solubility to be similar to 7 x 10(18) cm(-3) at 200 degrees C as determined from secondary mass spectrometry. The observed solubility Limit is more than eight orders of magnitude greater than that in crystalline germanium and the enthalpy of a solution of copper in amorphous germanium is estimated to be as low as 0.05 eV in the range of 20-200 degrees C. Copper is observed to diffuse more readily in amorphous germanium than in amorphous silicon, with an activation enthalpy as low as similar to 0.5 eV in the range of 20-200 degrees C. Interstitial diffusion is assumed to prevail and the trapping enthalpy of defects retarding the motion is found to be significantly lower in amorphous germanium (0.25 +/- 0.15 eV) compared to that in amorphous silicon (similar to 0.8 eV).