This article about competence and patient safety in anaesthesia was inspired by a statement in the 2015 AAGBI guidelines on monitoring during anaesthesia: 'the presence of an appropriately trained and experienced anaesthetist is important for patient safety during anaesthesia'. The review starts with a structured description of competence, presenting five dimensions of it; the first two dimensions are identical with the two classical attributes of competence, practical skills and theoretical knowledge. Concerning skills, the value of aiming for a high level of proficiency early in a traning programme is pointed out, and deliberate practice is given as an example of a pedagogical model where aiming for excellence is a core idea. For theoretical knowledge, the value of a deep approach to learning physiology and basic sciences is stressed. The third dimension (anaesthetists' non-technical skills), represents skills necessary for good team-work in the operating theatre. The two last dimensions of competence are the understanding of work and intuitive expert knowing. Understanding work means being aware of what the work is about, appreciating the different aspects of the anaesthetist's job. Intuitive expert knowing, lastly, concerns the tacit dimension of knowledge and skills, which enables professional experts to quickly find a working solution for most clinical problems. The final part of the review is about the 'when' and 'how' of competence assessment. The main message is the importance of assessing the competence of clinically active anaesthetists regularly during their whole career.