Background: The purpose of the first phase of the present research was to examine medical education accreditation practices around the world, with special focus on the Caribbean region, to determine the association of accreditation of medical schools with student/graduate performance on examinations. The aim of the second phase of this research was to evaluate the quality of a select group of accrediting agencies and the association of quality with student/graduate outcomes. Methods: In the first phase, all IMGs taking one or more examinations leading to ECFMG certification during the five-year study period (January 1, 2006 through December 31, 2010), and who graduated from, or attended at the time of testing, a school located in a country that met the accreditation inclusion criteria, were included in the study population. In the second phase, the quality of a select group of accrediting agencies was evaluated according to the criteria determined by a panel of experts to be the most salient features of an accreditation system. Discussion: The purpose of this study was to investigate the USMLE performance of graduates of international medical schools who voluntarily seek ECFMG certification based on variables related to the accreditation of their medical education programs. In this study, for the self-selected population who took examinations during the study period, accreditation was associated with better performance in specific regions and for some examinations. Of the three examinations, the existence of a system of accreditation had the strongest association with Step 1 performance for the global and Caribbean groups. Many accreditation criteria are directly related to aspects of the preclinical phase of education. The association between accreditation and Step 2 CS was positive for all three groups of students/graduates, although systems of accreditation may have less direct impact on student performance on clinical examinations as students' experiences in the clinical phase are likely more varied. Of the three groups, the existence of accreditation systems had the greatest associated with examination performance in the Caribbean, an important finding considering the large numbers of IMGs educated in this region seeking ECFMG certification and ultimately treating U.S. patients. The quality of accrediting agencies, as determined by the number of essential elements utilized in the systems, was positively associated with performance for Step 1 and Step 2 CS, but not Step 2 CK. The finding supporting the importance of a high-quality accreditation system on Step 2 CS performance is important due to the purpose of this examination in evaluating a physician's skills in a real world setting. This study lends some support to the value of accreditation. Due to the substantial resources needed to design and implement accreditation processes, these results provide some positive evidence beyond face validity, especially in the Caribbean region, that quality assurance oversight of educational programs is associated with the production of more highly skilled physicians, which in turn should improve the health care of patients in the United States and around the world. (Abstract shortened by UMI.) [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]