Innovations in medical device technology have greatly expanded the range of therapeutic options available to physicians and their patients. The understanding of treatment effects from the patient's perspective is an essential component of a comprehensive assessment of any new therapy, including medical devices. The term “patient-reported outcomes” (PROs) has been growing in use to refer to a cluster of variables such as health-related quality of life, symptoms, physical functioning, psychological well-being, treatment satisfaction, and treatment preferences. As in drug trials, the use of PROs in device evaluation has several methodological challenges, ranging from general concerns about interpretation, to more specific issues related to study design and regulatory approval (use of PROs as primary end points, incorporation in labeling, and product promotion). Successful approaches for integrating PROs into device evaluation trials include the careful selection of appropriate, interpretable PRO end points, accounting for possible confounding factors, and the use of alternatives to placebo-controlled trial designs, such as single-arm pre–post, observational, and registry studies, when the use of placebo control groups is not feasible. This article discusses the potential value and difficulties in measuring PROs in device studies.