Reliability and validity of the Flanagan Quality of Life Scale (QOLS) were tested in four chronic illness groups. Open-ended questions and four instruments, the QOLS, Duke-UNC Health Profile (DUHP), Life Satisfaction Index (LSI-Z), and either the Arthritis Impact Measurement Scales (AIMS) or the Ostomy Adjustment Scale (OAS) were administered by telephone interview and mailed questionnaires to 227 adults three times over 6 weeks. Subjects generated verbal responses that substantiated the content validity of the QOLS. Stability reliability estimates for all instruments ranged from .53 to .90. Cronbach's alpha coefficients averaged .87 for the QOLS. Appropriate validity coefficients indicated both convergent and discriminant construct validity.