Because the central nervous system is so specialized that they have lost the ability to divide and generate new cells right after birth, various permanent impairments result inevitably from injury or dysfunction of the system. With advent of the neuroimaging technique such as MRI or CT scan and technical advance in molecular genetics, many neurological diseases are newly detected. Recently, the government has laid a foundation for comprehensive welfare programs for the disabled not only due to trauma or injury but also medical illness such as stroke, epilepsy, or muscular diseases. Consequently, there are so many things to do for neurologist to evaluate the degree of disability due to neurological disease and it is necessary to prepare a clear disability rating system such as the guidelines of American Medical Association and McBride's principle. At present the criteria for evaluation of disability degree are based on the laws such as the labor standard law, the national reparation law and the industrial accident compensation and insurance act in Korea, however, the criteria for evaluation of disability caused by neurological illness are too inclusive and vague to make a concrete rating the disability. Therefore, new looks at the impairment criteria for nervous system is needed. In this article, I would like to investigate the present medical criteria in evaluating and rating the neurologically disabled patients in Korea.