There are conflicting reports regarding the occurrence of cardiovascular events after a major earthquake. To understand the impact of the Great East Japan Earthquake on cardiovascular events, we retrospectively examined the clinical records prepared by emergency room physicians between 2009 and 2011 (n = 66,244), and compared the occurrence of these events between 2011 and 2009, and 2011 and 2010. There was a significant increase in the number of patients with cardiovascular events during the 3 week period after the earthquake in 2011 (n = 106) compared with that during the same period in 2009 (n = 72) or 2010 (n = 65) (P = 0.002). The number of patients with acute coronary syndrome or congestive heart failure in March 2011 was significantly increased compared with 2009 or 2010, however, there were no significant increases in 2011 in other cardiovascular events including stroke, aortic dissection, pulmonary thromboembolism, or out-of-hospital cardiac arrest compared with 2009 or 2010. These findings suggest that the incidence of cardiovascular events may have been heterogeneous after the disaster.