Although there have been a few articles discussing laughter in social work, social work is not normally associated with humour and laughter. The paper explores the use of non-seriousness in interview interactions with Approved Mental Health Professionals (AMHPs) using analytical insights gained from ethnomethodology, conversation analysis and socio-linguistics. Excerpts from empirical data from individual narrative interviews will be used to show how social work identity can be accomplished through humour and laughter. The significance of the key ethnomethodological concepts of unique adequacy, vulgar competency and indexicality will be used to inform the analysis of gallows or bleak humour, ironic banter about the ‘other’ and the telling of troubles. In the interviews, non-seriousness was successfully accomplished by two ‘strangers’. It is argued that as group members of a specialised group, we share a deep competence in the haecceity or the ‘just thisness’ of the social work trade. Thus, this can be seen as a powerful demonstration of the competencies involved in being a bona fide member of a collectivity.