Objectives: Our aim was to evaluate how organizations that develop patient decision aids conduct their evidence summarization process and assess whether their current processes provide sufficient information to instill confidence that patient decision aids are trustworthy and up to date. Study Design and Setting: We identified 23 organizations from a public inventory of patient decision aid developers and included only organizations that have produced five or more tools. These organizations were asked to complete a 17-item survey and to share relevant documents. Results: Of the 23 organizations, 18 completed the survey, and 15 were eligible for analysis. Most organizations reported using existing systematic reviews and clinical practice guidelines. Seven of 15 had a documented approach for summarizing evidence, but the documents offered varying levels of detail. Common steps identified are tool-relevant question formation, search strategies, evidence appraisals, and updating policies. Conclusions: Organizations do not use a standardized process to summarize evidence for the patient decision aids that they develop. This is problematic, given that the information they contain is known to influence patients’ decisions. Further attention to how organizations summarize evidence for these tools is required.