Patients are increasingly seeking information about physicians online. Nearly 60% report that online reviews are important when choosing a physician. 1 Because publicly reported quality data are not reported at the physician level, patients must consult physician-rating websites to find such reviews. 2 The purpose of this cross-sectional study was to describe the structure of commercial physicianrating websites and the quantity of physician reviews on these sites. Methods |During September 2016, we searched Google for websites that allowed patients to review physicians in the United States, using search terms such as rate my doctor. We included active sites that were written in English, available to the public, allowed patients to leave reviews, did not require a subscription, and allowed searching by physician name. We excluded websites that were affiliated with an insurance company or health system or were limited to a single specialty. We cross-referenced search results against a published list, 3 added any websites that met inclusion criteria, and recorded website characteristics. We then used publicly available lists of registered and active physicians to identify a random sample of 600 physicians from 3 metropolitan areas (Boston, Massachusetts; Portland, Oregon; and Dallas, Texas). We searched each website for reviews and calculated mean and median number of reviews per physician per site using SAS (SAS Institute), version 9.3.