OBJECTIVE: To investigate how health professionals in hospital wards that have voluntarily initiated user involvement negotiate user knowledge into their professional knowledge. METHODS: Qualitative interviews were conducted with 18 health professionals from 12 hospital wards in Central Norway. RESULTS: The main value to health professionals of initiating user involvement was gaining access to user knowledge. Two functions of user knowledge were identified--user knowledge as an alternative to professional knowledge and user knowledge as support for professional knowledge. The need for good professional practice was used as an argument for closing professional fields to user involvement. Professionals were also under scrutiny from other discourses, such as scientific-bureaucratic medicine, which had a strong impact on how user involvement was carried out. CONCLUSION: Health professionals saw knowledge transfer as valuable, but ultimately valued professional knowledge above user knowledge. PRACTICE IMPLICATIONS: Even health personnel who embrace user involvement limit the influence of user knowledge on their own professional work. It seems necessary that user involvement be included in health policy and practice guidelines at hospital wards, if it is desirable that user knowledge influence professional knowledge and everyday work.