This review summarizes those neurological diseases which are accompanied by a drooping of the upper lid, due to weakness of the m. levator palpebrae or m. tarsalis respectively. After connatal ptosis with or without involvement of other bulbar muscles the different types of muscular dystrophies are mentioned. Myositis, disturbances of potassium regulation and myasthenia gravis are other causes of ptosis. Diseases involving the oculomotor nerve (aneurysm, upper herniation, cavernous sinus thrombosis, orbital cavity processes, superior orbital fissure syndrome) may lead to associated ptosis. Metabolic disturbances, such as diabetes mellitus, Wernicke's encephalopathy and botulism may be accompanied by ptosis. Infectious diseases such as polyneuritis, meningitis or encephalitis can lead to ptosis. Sympatholytic ptosis is due to diseases of the central or peripheral course of the sympathetic nerve from the diencephalon via the cervical medulla, the neck, internal carotid artery to the superior orbital fissure. This type of ptosis is usually accompanied by miosis and often by sweating loss on the same side.