An unavoidable consequence of the aerobic mechanism is the production of super-oxides and peroxides known as "Reactive Oxygen Species" (ROSs). These substances can trigger a number of biological reactions not particularly dangerous at physiological concentration. However, in presence of iron such reactions greatly enhance the radicals production and, in particular, determine the release of strongly reactive and toxic radicals as the hydroxyl radical (OH.). Many chronic inflammatory conditions share this underlying disequilibrium of the iron induced radical-antiradical balance. Aim of the present review is to enlighten the role of the free or weakly chelated portion of iron in vascular and cardiac diseases.