AlPdMn quasi-crystalline specimens were deformed at low temperatures using a high-confining-pressure device. The microstructures, observed in each sample by transmission electron microscopy, depend on the deformation temperature and show that plastic deformation is accompanied by dislocation movements. A detailed analysis of the dislocation configurations shed light on the low temperature deformation mechanisms. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.