The invention relates to an iron oligosaccharide compound with improved stability comprising a hydrogenated oligosaccharide in stable association with ferric oxyhydroxide, the content of dimer saccharide in said hydrogenated oligosaccharide being 2.9% by weight or less, based on the total weight of the hydrogenated oligosaccharide. In further aspects is provided a process for preparing said compound as well as the use of said compound for preparation of a composition for treatment of iron deficiency anaemia.