The psychometric assessment of a new measure of self-efficacy at discharge from an acute care hospital, The Ability for Self Care scale is reported. The study consisted of three phases: instrument development, reliability assessment, and validity assessment. The Ability for Self Care scale contains 22 items rated on a 5-point ordinal scale. Seven behaviors or tasks are represented including: activities of daily living, diet, medications, treatments/therapeutic regimens, physician/health care contacts, therapeutic exercise, and overall self care self-efficacy. A total of 350 patients being discharged from the hospital to a home setting participated. Substantial internal consistency was demonstrated. Validity testing included hypothesis testing. Ability for Self Care scores were significantly related to social support, previous ability, and functional status, and anxiety.