Since 2017, opportunistic screening for cognitive impairment takes place at the geriatric ward of a local hospital in Sweden. Persons above the age of 65 who are admitted to the ward, who have not been tested for cognitive impairment during the last six months nor have a previously known cognitive impairment, are offered the Mini-Mental State Examination and the Clock-Drawing Test. This article analyses what the opportunistic screening practice means for patients and healthcare professionals. It combines a phenomenologically-oriented focus on subjectivity and sense-making with a focus that is inspired by science and technology studies on what the tests become within the specific context in which they are used, which allows a dual focus on subjectivity and performativity. The article shows how the tests become several different, not infrequently seemingly contradictory, things: an offer, an important tool for knowledge-production, something unproblematic yet also emotionally troubling, something one can fail and an indicator that one belongs to a risk group and needs to be tested. Further, the article shows how the practice is shaped by the sociocultural context. It examines the role of the affective responses to the test for subjectivity - particularly patient subjectivity - and offers a set of recommendations, if this practice were to expand to other hospitals.