Knee osteoarthritis (OA) is a major cause of disability in older adults. However, there is limited research on the daily experience of living with knee OA. We aimed to offer insight into the beliefs of patients with knee OA about their illness and treatment.Twenty-four semi-structured interviews were conducted with 17 women and 7 men with physician-diagnosed knee OA, aged between 48 and 84 years (mean = 62, SD = 7). The audio-taped interviews lasted from 30 min to 1 h, and were transcribed verbatim. The data were subjected to thematic analysis. The transcripts were independently coded by two researchers to increase reliability of coding.Six themes were developed and two of these are examined in further detail: (i) Illness representation and (ii) Beliefs about the medical and surgical control of pain. Illness representation comprised beliefs about people's understanding of OA and their pain experience, as well as expectations about the course of illness. The second theme presented experiences of limited pain relief and concerns about the use of drugs and surgery.Exploring illness representations and beliefs about medical and surgical control of pain may provide the basis for initiating psychological interventions for people with knee OA.People with knee OA place pain at the core of their living, and hold beliefs about knee OA being an incurable disease of a progressive nature, linked to specific causal factors. People with OA have concerns and worries about use of medication to control pain, and are ambivalent towards relying on medical or surgical interventions. Exploring and addressing patient illness beliefs and treatment expectations may help improve concordance with and outcomes from intervention.