Published in Journal of Advanced Nursing, the following study investigates the effects of a primary nursing care delivery system on some work-related factors of nurses in long-stay psychiatric care settings. Two effects were investigated in this study: An effect due to a deliberate introduction of primary nursing and an effect due to more autonomous changes during the intervention period. The results of the analyses of the former are quite strong and show an increase in autonomy, a decrease in complexity and personal care tasks, and a better alignment of the nurses with the patient-oriented care model.