The usefulness of functional scales has become clear in the past few years, to evaluate patients with dysimmune peripheral neuropathies. Functional scales which measure the real impact of the disease process in our patients will probably be increasingly used in future therapeutic trials. By contrast with neurological disorders leading to pure motor involvement, peripheral neuropathies are difficult to evaluate, due to their clinical polymorphism. However, efforts have been made in the past ten years in order to validate functional scales that may be routinely used by neurologists for dysimmune neuropathies. New scales will probably arise in the next few years, to be used in neuropathies from other causes. These scales will have to be strictly validated to be used in the daily medical practice.