An atomistic model for self-interstitial extended defects is presented in this work. The model is able to predict a wide variety of experimental results by using a limited set of assumptions about the shape and emission frequency of extended defects, and taking as parameters the interstitial binding energies of extended defects versus their size. The model accounts for the whole extended defect evolution, from the initial small irregular clusters to the {3 1 1} defects and to the more stable dislocation loops. It predicts the extended defect dissolution, supersaturation and defect size evolution with time, and it takes into account the thermally activated transformation of {3 1 1} defects into dislocation loops. Moreover, the model is also used to explore a two-phase exponential decay observed in the dissolution of {3 1 1} defects. (C) 2008 Elsevier Ltd. All rights reserved.