Evaluation of nursing students in the clinical field requires the clinical teacher to make judgements regarding student progress in a number of areas. In this study concepts of role theory, oppressed group behaviour and the ethics of caring emerged and were used as conceptual frameworks to interpret the data relating to the evaluation of undergraduate students. The number of experienced faculty available for clinical teaching and evaluation has become inadequate and a large number of casual or sessional clinical teachers are employed to teach students in the clinical field. Despite the well documented problems associated with clinical teaching and the use of inexperienced clinical teachers, sessional clinical teachers are nevertheless expected to evaluate student success in meeting the clinical requirements of the nursing course, often resulting in disparate decisions for students. A phenomenological study was carried out using unstructured interviews and written clinical scenarios, to explore the evaluation process from the perspective of the sessional clinical teachers. Research findings indicate that although the sessional clinical teachers were skilled at identifying student problems, they were reluctant to make difficult evaluation decisions, due to low self-esteem, role conflict and their ethic of caring. It seems that gender socialization, patriarchal dominance and apprenticeship training had effected their confidence in their own decision making. The implications of such findings are of concern for the ongoing credibility and integrity of nursing courses, as clinical teachers have an influence on the nursing profession through the preparation of its practitioners.