Abstract: Sense-Making, a qualitative research method, was used to obtain and analyse data from interviews with 10 registered nurses, in order to study reflective thinking in actual nursing practice. Ten non-routine nursing situations were analysed for the presence of reflective thinking. Reflective thinking was extensively manifest, especially in moments of doubt and perplexity, and consisted of such cognitive activities as comparing and contrasting phenomena, recognising patterns, categorising perceptions, framing, and self-questioning in order to create meaning and understanding. Self-questioning was identified as a significant process within reflective thinking. By exploring and analysing the type of questions respondents were asking themselves, the study uncovered three hierarchical levels of reflective thinking, focussed on action, evaluation and critical enquiry. The findings of this study resulted in the development of a model of reflective thinking, which is discussed in terms of the implications for learning in nursing practice.