Frailty is increasingly used in clinical settings to describe a physiological state resulting from a combination of age-related co-morbidities. Frailty also has a strong ‘lay’ meaning that conjures a particular way of being. Recent studies have reported how frail older people perceive the term frailty, showing that frailty is often an unwanted and resisted label. While there are many scores and measures that clinicians can use to determine frailty, little has been published regarding how health-care professionals use and make sense of the term. This paper reports the findings of a qualitative study that explored how health professionals perceive frailty. Forty situated interviews were conducted with health-care professionals working in an emergency department in the English Midlands. The interview talk was analysed using discourse analysis. The findings show that the health professionals negotiate an ‘ideological dilemma’ – a tension between contradictory sets of meanings and consequences for action – based on their ‘lay’ and clinical experience of the term frailty. It is concluded that this dilemma could have a negative impact on the assessment of frailty depending on the system of assessment used.