The Internet is an important source of medical information. It is expected that the use of online sources will improve clinical decisions. This study aims to evaluate online information seeking behavior of physicians of Mashhad University of Medical Sciences on the use of online clinical evidence. A cross-sectional, questionnaire-based study was carried out between November and December 2014 in the five academic hospitals. A total of 252 physicians completed the questionnaire. The majority of physicians (63.6 of specialists and 58.5% of residents) had no internet access in their consultation and visit rooms. The majority of physicians (77.8% of specialists and 80% of residents) respectively used Google, as well as 67.5% specialists and 52.2% residents always used Medline or PubMed, among electronic sources, to searching for information. The main reasons for physicians' dissatisfaction with the Internet, as a source of health information, were lack of access to medical sources owing to the non-targeted filtering (61% specialists and 74.6% residents) and very slow connection of the Internet (75.6% specialists and 83.1% residents). It is recommended that medical informatics training programs should be incorporated, where physicians are required to search for health information in the Internet