There is growing evidence supporting the relationship between pain-related fear and functional disability in chronic musculoskeletal pain conditions. In osteoarthritis (OA) patients the role of pain-related fear and avoidance has received little research attention so far. The present study investigates the degree to which pain-related fear, measured with the Tampa Scale for Kinesiophobia (TSK), influences daily functioning in OA patients. The purpose of the present paper was twofold: (1) to investigate the factor structure of the TSK in a sample of OA patients by means of confirmatory factor analysis; and (2) to investigate the role of pain-related fear in OA compared to other factors, such as radiological findings and level of pain intensity. The results show that TSK consists of two factors, called 'activity avoidance' and 'somatic focus', which is in line with other studies in low back pain and fibromyalgia. Furthermore, pain-related fear occurred to a considerable extent in this sample of osteoarthritis patients and was negatively associated with daily functioning. Level of pain and level of pain-related fear were significantly associated with functional limitations. Radiological findings were not significant predictors and when compared to pain-related fear they were not significant. These findings underscore the importance of pain-related fear in daily functioning of OA patients. Therefore, treatment strategies aiming at reduction of pain-related fear in OA patients need to be developed and investigated.