Tensile creep experiments on HDPE with a duration of 8 weeks were performed at a temperature of 23 degrees C. Since the tests were performed 32 weeks after moulding of the specimens, the effect of ageing during creep can be neglected. The creep strain can be fitted up to 5% using the Leaderman model in terms of true stress and true strain. However, the yielding ar larger strain levels cannot be described with this model. A good fit of the creep data, including yield behaviour, is obtained with a model of two processes in parallel, each having its own time-stress shifting function. Predictions of this model for constant strain rate experiments show good agreement with observations. (C) 2000 Elsevier Science Ltd. All rights reserved.