Purpose: Inappropriate use of urinary and intravenous catheters is still frequent. The use of catheters is associated with some serious complications, such as health care associated infections (HAIs). An efficient way to reduce HAIs is to avoid inappropriate use of catheters, but the role for patients in quality improvement initiatives is unclear. The aim of this study is to investigate patients knowledge and experience with catheters, to design patient interventions to reduce inappropriate catheter use. Methods: We assessed patient’s knowledge and experience with catheters using a self report questionnaire, and included patients with a urinary and/or peripheral intravenous catheter (PIVC) during the baseline measurements of a quality improvement project to reduce inappropriate catheters use. Results: A total number of 82 patients completed the questionnaire, of which 49 had a urinary catheter and 72 a PIVC. Patients were unaware about the indication for their urinary catheter in 20.9% and PIVC in 19.5%. Nevertheless, 65.3% reported symptoms due to urinary catheters and 37.5% for PIVCs. Interestingly, only 25.5% and 22.4% reported that they would ask their doctor if the catheter could be removed. Conclusions: There is a lack of knowledge about the indication for having a urinary and peripheral intravenous catheter in a substantial part of patients. Although catheters cause symptoms, patients in general do not ask if the catheter could be removed. Doctors should give more information and ask more questions about catheters to their patients. Quality improvement initiatives stimulating patients to actively participate in their treatment are needed.