Oxide Dispersion Strengthened (ODS) steels are candidates for nuclear applications. ODS are produced by mechanical alloying of Fe-14Cr, Y2O3 and TiH2 powders and consolidation at 1100 °C, resulting in finely dispersed nano-oxides. Their precipitation kinetics has been quantitatively determined by in-situ Small Angle X-ray Scattering during continuous heating up to 1100 °C. Clusters, found in the as-milled state start growing at 450 °C until 1100 °C, while almost no coarsening was recorded during subsequent isothermal annealing. The nano-oxides resulting from these in-situ experiments were found to be representative of those in materials processed by hot isostatic pressing and hot extrusion.