Summary: Multicenter clinical trials are important research tools. Planning a multicenter clinical trial is a long and arduous task that requires substantial preparation time. In this guide, the authors discuss the steps used to plan a multicenter clinical trial. A preplanning phase, which involves formulating and refining a research question and conducting pilot studies, is detailed, and the planning phase, which involves the acquisition of funding to support the coordination and preparation of a multicenter clinical trial, culminating in the submission of an R01 grant, is described. An essential asset to planning a multicenter clinical trial is the fluidity with which all collaborators work together toward a common vision. The philosophy among collaborators should be consensus and commitment and is emphasized by the development of a consensus-assisted study protocol. Most important are the recruitment of centers and co-investigators who are dedicated, collaborative, and selfless in the team effort to achieve goals that cannot be reached by a single-center effort.