Background There is a little empirical evidence to determine which, if any, monitoring practices best achieve the goals of trial monitoring set forth in ICH E6 under the variable circumstances of different clinical trial settings.Purpose The purpose of this project was to describe current methods of monitoring clinical trials and to explore the rationale for the use of those methods.Methods An electronic survey of known monitoring practices was developed and sent to over 200 organizations involved in conducting clinical research. The survey collected information on institutional demographics, methods of overall study oversight, use of risk-based monitoring and factors that influence assessments of risk, and details on quality assurance and monitoring practices.Results Seventy-nine organizations completed the survey; our analysis included the 65 organizations that indicated they perform clinical trials. Data from the survey indicate that a wide variety of monitoring practices are currently being employed. Eighty-three percent of respondents use centrally available data to evaluate site performance, but only 12% of respondents always or frequently used centralized monitoring to replace on-site visits. Eighty-seven percent of respondents indicated that they always performed on-site visits. This varied by type of organization, with 31% of academic coordinating centers/cooperative groups/government organizations always performing on-site monitoring visits versus 84% of other organizations. The rationale for using a specific monitoring approach does not appear to be based on empirical evidence. Fifty-four percent of respondents stated that 'usual practice' determined the frequency with which they conducted on-site monitoring visits.Limitations The overall response rate to our survey was only 30%; thus, we may not have captured the full variance of current monitoring practices, and our responding sample may not be representative.Conclusion These findings underscore the necessity of research to provide an evidence base for monitoring practice.