The neurodegenerative diseases that affect almost a million Spaniards produce the progressive death of the neurons in different areas of the nervous system. Most of these diseases follow a chronic and progressive course and are, thus, very disabling and the main source of dependence in the developed countries. Depending on the areas of the nervous system that are more affected by the neuronal loss, the neurodegenerative diseases can produce cognitive (e.g., Alzheimer), motor (e.g., Parkinson), sensorial, or a mix of symptoms. The ethiopathogenesis in most of the neurodegenerative diseases is unknown, and the available therapies are not too effective either. Almost all cases (>90%) appear sporadically and in less than 10% of the patients they are present in a familiar way. The sporadical neurodegenerative diseases seem to have a multifactorial origin, although aging is one of the most important risk factors. Research on neurodegenerative diseases is currently focused in the identification of the causes and mechanisms that make them appear and progress, in the generation of new drugs to be applied at the initial stages of the clinical process, and in the fine tuning of new advanced therapies. In the case of Parkinson disease, an intense investigation is being developed to complement and improve the current drug therapies, which are useful during the first stages of the disease. Together with the therapy based in the substitution of cells destroyed, there are also studies in the action of the neurotrophic substances that when applied to the brain halt or slow down the degenerative process, allowing functional recovery. Many of the vanguard investigations in neuroscience are aiming at avoiding that an aged brain becomes necessarily the source of the disease. Nevertheless, the perspectives of the advances in prevention or treatment of the neurodegenerative diseases in the short term are not overly flattering, so the medical control of these pathologies is without doubt one of the most urgent and passionate scientific challenges of our times.