This study strives to test a theoretical model of professional nurse work environments by linking conditions for professional nursing practice to burnout and, subsequently, patient safety outcomes. Using hospital-based nurses in Canada as subjects, the study found that nursing leadership played a fundamental role in the quality of work life regarding policy involvement, staffing levels, support for a nursing model of care (vs medical), and nurse/physician relationships. Staffing adequacy directly affected emotional exhaustion, and use of a nursing model of care had a direct effect on nurses’ personal accomplishment. Both directly affected patient safety outcomes. The results suggest that patient safety outcomes are related to the quality of the nursing practice work environment and nursing leadership’s role in changing the work environment to decrease nurse burnout.