The 'dynamic creep' behaviour of poly(aliphatic/aromatic-ester) (PED) multiblock copolymers has been evaluated by the hysteresis measurements method. The effect of the hard/soft segments concentration on the microphase separation in PED copolymers was determined by means of differential scanning calorimetry. The 'dynamic creep' of PED copolymers has been compared with poly(ether-ester) and segmented polyurethanes indicating on the good creep behaviour of PEDs compared to those materials. It was found that the hard segment content influences the creep behaviour of PED copolymers at ambient and elevated temperature indicating that stiffer materials are less susceptible to environmental conditions than polymers containing a high amount of the soft phase. PED copolymers compare very well with commercially available poly(ester-ethers) and show much lower creep compared to poly(ether-urethanes). (C) 2003 Elsevier Science Ltd. All rights reserved.