This paper examines teachers' experiences and displays of negative emotion as a means of partially exploring how identities at work might be formed and regulated. It uses the concepts of emotional labour and subjectivation to interrogate the negative emotions teachers may experience and/or express at work. It suggests that emotion display rules are developed and come to partially define the teacher self in tandem with overlapping, synthetically discussed discourses of the teacher as "moral/caring agent", "expert" and "purveyor of social control/social efficiency". The field of emotional labour is explored here using diary entries of teachers who were between their second and fifth year of teaching in Irish primary schools. Teachers' experiences are read with less of a concern for the original "authenticity" thesis of emotional labour in order to foreground an analysis of how certain truths about teachers' emotions are legitimated and solidified in the labour cycle. It is argued that spaces for multiple teacher identities and interrogation of emotional display must be carved out in teacher education. This space might include an acknowledgement of ambivalence towards the profession. (Contains 5 notes.)