The concept of the expert patient is an increasingly important one in healthcare policy and delivery. To date, however, there has been relatively limited consideration of the nature and characteristics of the knowledge and skills underpinning the role of expert patient or the relationship to more traditional health professional expertise. This article considers the emerging concept of the expert patient in the UK, its relationship to the emergence of the expert patient elsewhere (notably in Canada), together with exploration of the supporting rationales, assumptions and possible implications associated with the initiative.