Objective: Shared decision making (SMD) related to treatment and rehabilitation is considered a central component in recovery-oriented practice. Although decision aids are regarded as an essential component for successfully implementing SDM, these aids are often lacking within psychiatric services. The aim of this study was to use a participatory design to facilitate the development of a user-generated, web-based decision aid for individuals receiving psychiatric services. The results of this effort as well as the lessons learned during the development and usability processes are reported. Method: The participatory design included 4 iterative cycles of development. Various qualitative methods for data collection were used with potential end users participating as informants in focus group and individual interviews and as usability and pilot testers. Results: Interviewing and testing identified usability problems that then led to refinements and making the subsequent prototypes increasingly user-friendly and relevant. In each phase of the process, feedback from potential end-users provided guidance in developing the formation of the web-based decision aid that strengthens the position of users by integrating access to information regarding alternative supports, interactivity between staff and users, and user preferences as a continual focus in the tool. Conclusions and Implications for Practice: This web-based decision aid has the potential to strengthen service users' experience of self-efficacy and control as well as provide staff access to user knowledge and preferences. Studies employing participatory models focusing on usability have potential to significantly contribute to the development and implementation of tools that reflect user perspectives.