The Accreditation Council for Graduate Medical Education (ACGME) implemented work hour restrictions for physicians in training in 2003 that were revised July 1, 2011. Current published data are insufficient to assess whether such work hour restrictions will have long-term impact on residents' education. We searched computer-generated reports of hospital in-patient census, continuity clinic census, in-training exam scores and first-year resident attendance at educational conferences for the academic years 2010-2011 (August 1, 2010-May 31, 2011) and 2011-2013 (August 1, 2011-May 31, 2013). During the first year of the study period, the residents' inpatient internal medicine services admitted 1,754 patients; during this same period for academic years 2011-2012 and 2012-2013, the teaching services admitted 1,539 and 1,428 patients respectively, yielding a decrease of 16.4%. Monthly, these services cared for a mean of 27.1 (27.1/175.4 [15.4%]) fewer patients and 9.7 (9.7/34.4 [28.2%]) fewer patients per intern than in the previous year. No statistical difference was observed regarding continuity clinic attendance and in-training exam scores. Residents in the years following work hours restrictions attended more educational conferences. Implementation of 2011 ACGME work hour regulations resulted in fewer patients seen by first-year residents in hospital, but did not affect in-training exam scores. Whether these findings will translate into differences in patient outcomes, and quality of care remains to be seen.