The Professional Opinion Scale (POS) was developed to measure social work values orientation. Objective: A confirmatory factor analysis was performed on the POS. Method: This cross-sectional study used a mailed survey design with a national random (simple) sample of members of the National Association of Social Workers. Results: The study validated a 28-item POS retaining the four subscales described by Abbott, and the model fit was acceptable. Conclusions: Findings suggest that the POS may be useful in assessing social work values across the social work profession. (Contains 6 tables and 1 figure.)