The purpose of this study was to improve measurement of elder self-neglect by testing the psychometric properties of the Elder Self-Neglect Assessment (ESNA). Social workers, case managers, and adult protective services providers from 13 Illinois agencies completed a 77-item assessment for 215 clients suffering from self neglect. Analyses used Rasch item response theory and traditional validation approaches to test for dimensionality, model fit, and additional construct validation, resulting in a 62-item assessment. The ESNA met Rasch fit criteria with good internal consistency, item reliability, and construct validity. A 25-item short form also met Rasch criteria. A hierarchy of items associated with severity of abuse was produced by frequency of occurrence. ESNA indicators of self-neglect align into two broad categories: behavioral characteristics and environmental factors, which must be accounted for in a comprehensive evaluation. Theoretical refinements developed using the empirically generated item hierarchy may help to improve assessment and intervention.