New ways of working in critical care are emerging in response to increasing demands for care in the context of alimited critical care workforce. This review appraised the comparative safety, effectiveness and costs of new ways ofworking in critical care. All papers published in peer reviewed journals during 1990–2003 were utilised. A total of 933potentially relevant papers were identified. Secondary sources including policy papers, and experts within the field werealso used to inform this work. Initially 113 papers met the inclusion criteria. However, 58 of these described policy andsecular trends in critical care and were therefore used only to provide background information. A total of 55 paperswere then critically reviewed to provide academic focus on the subject area. Examples of comparative empirical researchon new ways of working were limited, but the review revealed research activity in the areas of: impact of workload;nursing, medical and organisational factors affecting patient outcomes; and methods to support workforce calculations.The findings suggest that research into longer-term patient outcomes is needed together with a proactive and strategicinterdisciplinary approach to practice, policy and research.