Quizzes are a ubiquitous part of the dementia social care landscape. This article explores why. Using an ethnographic approach which draws on close analysis of communication, we examine dementia quizzes as a ‘social practice’, and what such a lens can tell us about their popularity in social care settings. Vignettes of real interactions drawn from ten different quizzes recorded in four different group settings attended by 28 people living with dementia and 15 staff members are presented to highlight particular issues. We show that the conditions of post-diagnosis dementia social care are uniquely well suited to an activity such as quizzes which are malleable, requiring little preparation or materials, and impose a communication framework which can help to organise the interactional space. Quizzes also draw on previously forged interactional competences, such as turn-taking and question–answer sequences, a skill that has been shown to persist even as dementia progresses. Finally, we argue that the meaning of quizzes with people with dementia feeds into wider societal values and associations attached to memory, dementia and personhood. The extent to which quizzes are akin to a ‘test’ or a fun and enjoyable social activity rests in how they are enacted. We suggest that practice can be adapted, developed and made more inclusive through input from people living with dementia themselves.