The olfactory mucosa, located in the nasal cavity, is the only nervous tissue that is exposed to the external environment and easily accessible in every living individual. In addition, this organ is home of a continuing neurogenesis that is sustained by a large population of stem cells. Here, we describe a method for biopsying olfactory mucosa from human nasal cavities and isolating multipotent adult stem cells that can be used to either identify biomarkers in brain disorders or repair the pathological/traumatized nervous system.