Atomistic simulations have been used to characterize the interaction and mobility of small clusters of self-interstitial atoms (SIAs) in dilute Fe-Cr alloys. The variety of migration mechanisms for Di- and Tri-SIA clusters in the bcc Fe matrix were studied using the nudged elastic band method. The corresponding binding and migration energies for the SIA clusters interacting with isolated Cr atoms and Cr-Cr close pairs were calculated using the two-band model interatomic potential. The obtained results are discussed in the light of available experimental data for dilute Fe-Cr alloys and are compared with results obtained using ab initio calculations. (C) 2009 Elsevier B.V. All rights reserved.