Traditional models of patient care delivery include total patient care and functional, team, and primary nursing. These models differ in clinical decision making, work allocation, communication, and management, with differing social and economic forces driving the choice of model. Studies regarding quality of care, cost, and satisfaction for the models provide little evidence for determining which model of care is most effective in any given situation. Despite lack of evidence, newer models continue to be implemented. This article compares the advantages and disadvantages of models, critiques the existing studies, and offers recommendations regarding the evidence needed to make informed decisions regarding care delivery models.