Many patients diagnosed with prostate cancer search for information on robotic prostatectomy on the Web. We evaluated the quality, popularity, accessibility, reliability, and readability of 43 robotic prostatectomy Web sites. Results showed medium to high ratings in all domains of quality and poor readability of Web sites. Physicians should guide their prostate cancer patients to Web sites with high-quality and adequate readability. Background: Many patients diagnosed with prostate cancer search for information on robotic prostatectomy (RobP) on the Web. We aimed to evaluate the qualitative characteristics of the mostly frequented Web sites on RobP with a particular emphasis on provider-dependent issues. Materials and Methods: Google was searched for the term "robotic prostatectomy" in Europe and North America. The mostly frequented Web sites were selected and classified as physician-provided and publically-provided. Quality was measured using Journal of the American Medical Association (JAMA) benchmark criteria, DISCERN score, and addressing of Trifecta surgical outcomes. Popularity was analyzed using Google PageRank and Alexa tool. Accessibility, usability, and reliability were investigated using the LIDA tool and readability was assessed using readability indices. Results: Twenty-eight Web sites were physician-provided and 15 publically-provided. For all Web sites, 88% of JAMA benchmark criteria were fulfilled, DISCERN quality score was high, and 81% of Trifecta outcome measurements were addressed. Popularity was average according to Google PageRank (mean 2.9 +/- 1.5) and Alexa Traffic Rank (median, 49,109; minimum, 7; maximum, 8,582,295). Accessibility (85 +/- 7%), usability (92 +/- 3%), and reliability scores (88 +/- 8%) were moderate to high. Automated Readability Index was 7.2 +/- 2.1 and Flesch-Kincaid Grade Level was 9 +/- 2, rating the Web sites as difficult to read. Physician-provided Web sites had higher quality scores and lower readability compared with publically-provided Web sites. Conclusion: Websites providing information on RobP obtained medium to high ratings in all domains of quality in the current assessment. In contrast, readability needs to be significantly improved so that this content can become available for the populace. (C) 2015 Elsevier Inc. All rights reserved