Self-neglect, the most common form of elder mistreatment seen by Adult Protective Service Agencies across the United States, is an often unrecognized geriatric syndrome characterized by squalor and unsafe living circumstances. It is a result of medical, neurologic, or psychiatric disorders coupled with lack of capacity for self-care and self-protection in the absence of necessary services or medical care, and leads to increased morbidity and mortality. Clinicians should evaluate self-neglecters and plan interventions based on comprehensive geriatric assessment and capacity assessment. State and federal policies are needed to address the pressing needs of this vulnerable population of seniors.