Abstract: Effective nursing prioritisation of the patient need for care is integral to daily nursing practice but there is no formal acknowledgement or study of this concept. Utilising the retroductive research strategy of critical realism, this thesis explores the nursing literature for the tacit knowledge of the discipline about nursing prioritisation and proposes a 'fit' for nursing prioritisation of the patient need for care within the bigger picture of nurse clinical decision-making. The tacit knowledge discerned within the literature indicates that nurses use discretionary judgment and ongoing assessment to determine the relative importance of the many aspects of individual patient situations as they unfold. Such nursing prioritisation takes place concurrently between the competing or even conflicting needs of the several individual patient presentations within the nurse's caseload. Varied frames of reference within different practice settings create specific imperatives on this dynamic and non-sequential process. Starting with an initial set of studies in the 1960s, study of clinical decision-making in nursing has created a significant body of knowledge encompassing a range of approaches. Nursing prioritisation of the patient need for care is most readily discerned in the interpretive perspective and in the plain language descriptions of nurse decision-making. Within the selected literature it is apparent that nursing prioritisation of the patient need for care is an advanced skill of nursing that is developed in practice and honed through experiential learning.