Background and Objectives: The aim of this study was to investigate the differences of characteristics and outcomes between aortic intramural hematoma (IMH) and IMH with aortic dissection (AD) in a single tertiary center for recent 5 years. Methods: A total of 112 patients were divided into 2 groups; pure IMH group (n=59, 21 males, 65.1짹10.8 years, type A in 29 patients) vs IMH group (n=52, 25 males, 61.6짹13.7 years, type A in 26 patients). Baseline clinical, laboratory, electrocardiographic, echocardiographic, computed tomographic angiography (CTA) findings, and clinical outcomes were compared. Results: Baseline clinical, laboratory, electrocardiographic, and echocardiographic findings were not different between the groups. On CTA findings, the aortic calcification (3.4% in pure IMH vs 23.1% in IMH with AD, p=0.002) was significantly prevalent in IMH with AD than in pure IMH. The maximal size of aortic knob (47.7짹9.7 mm in pure IMH vs 52.2짹12.4 mm in IMH with AD, p=0.038) and ascending aorta (43.9짹6.2 mm in pure IMH vs 47.1짹7.8 mm in IMH with AD, p=0.019) was significantly larger in IMH with AD than in pure IMH, but the maximal size of descending aorta, involve aortic segments, and maximal hematoma thickness were not different. Twenty one patients (18.9%) were died during hospitalization and clinical follow-up, and the mortality was not different between the groups (17.0% in pure IMH vs 21.2% in IMH with AD, p=ns). Age (the survived: 63.4짹10.1 years vs the dead: 73.6짹10.0 years, p=0.005 in pure IMH, the survived: 59.7짹13.4 years vs the dead: 68.9짹12.6 years, p=0.041 in IMH with AD) and the maximal size of the involved aortic segments (the survived: 41.2짹11.1 mm vs the dead: 49.6짹11.7 mm, p=0.014 in pure IMH, the survived: 43.0짹12.3 mm vs the dead: 50.7짹15.7 mm, p=0.042 in IMH with AD) were significantly associated with mortality in both groups. The decreased level of hemoglobin (the survived: 12.5짹2.0 g/dL mm vs the dead: 10.6짹1.3 g/dL, p=0.016) and elevated cardiac troponin I (the survived: 0.03짹0.04 ng/mL vs the dead: 0.29짹0.58 ng/mL, p=0.011) was significantly associated with mortality in pure IMH, but not in IMH with AD. Conclusion: The present study suggested that pure IMH and IMH with HD had similar characteristics and outcomes except that IMH with AD developed in larger sized aorta with calcification than pure IMH. Older age and the larger aortic diameter of the involved segments was significant predictor of mortality in IMH regardless of the presence of combined AD. Lower hemoglobin level and elevated cardiac troponin was significant predictors of mortality in pure IMH.