This article is based on qualitative research into how theatre nurses develop and use their professional judgement in practice. Newly qualified and experienced theatre nurses, as well as experienced surgeons were interviewed in order to gain insight into the subject.

The theoretical frame is based on Aristotle’s concept of phronesis, or practical wisdom. This research shows that professional judgement happens neither by chance nor by coincidence. Much theoretical and professional practice lies behind excellent professional judgement. Personal quality was also considered important.

Professional judgement and knowledge go hand in hand. Narrative and practical action are documentation of the evidence of professional judgement.