This "Legal Briefing" column covers recent legal developments involving patient decision aids.This topic has been the subject of recent articles in JCE. It is included in the 2010 Patient Protection and Affordable Care Act. And it has received significant attention in the biomedical literature, including a new book, a thematic issue of Health Affairs, and a recent article in the New England Journal of Medicine. Moreover, physicians and health systems across the United States are increasingly integrating decision aids into their clinical practice. Both federal and state laws play a significant role in promoting this expanded use. On the other hand, concerns about liability could stymie development and implementation. We categorize legal developments concerning patient decision aids into the following five sections: 1. Development of decision aids. 2. Effectiveness of decision aids. 3. Federal regulation of decision aids. 4. State regulation of decision aids. 5. Legal concerns regarding decision aids.