We report on the particle diameter dependence of the growth rate of the InSb segment of InAs-InSb heterostructured nanowires grown by chemical beam epitaxy. The analysis of the growth rate reveals that the growth is limited by the Gibbs-Thomson effect and the effect of NW lateral dimensions on the nucleation rate during the layer by layer growth. In the temperature range explored, the surface diffusion of adatoms toward the particle and the growth temperature are not affecting the growth rate. (C) 2010 Elsevier B.V. All rights reserved.