Purpose. Validate, through factor analysis, the reliability and contents of the Appraisal of Self-care Agency Scale (ASA) in a hospital institution. Methods. This is a methodological study with secondary data for a sample of 201 adult patients listed in the database on chronically ill patients at Tunjuelito Hospital in Bogota, Colombia. Internal consistency (Cronbach alpha) and the factor structure were processed in SPSS11.5®. Results. The analysis of the principal components indicates a structure comprised of nine factors that explain 65.87% of the total variance. The instrument showed a Cronbach alpha of 0.68 and 0.74 corrected. Conclusion. The assessed Spanish version of the ASA was found to have psychometric properties that are valid and adequate for application in the different fields of nursing practice in Colombia