Hypertension is a risk factor for aortic dissection. Besides hypertension, associated factors for incidence of aortic dissection are not clear. The aim of this study was to examine whether other factors exist by an epidemiologic case–control approach. 240 consecutive cases suffering from acute aortic dissection were hospitalized in our university from 1989 to 2000. Blood chemistries and other information obtained immediately after admissions for the first attack were available in 226 patients. A case–control approach was performed by frequency matching age, sex, and history of hypertension in the remaining 226 cases with those of 226 healthy controls drawn from a similar geographic catchment area and all observed in 1989. The mean albumin (3.6 ± 0.5 vs. 4.3 ± 0.2 g/dL: P<.001) level of cases was significantly lower than that of controls (odds ratio: 0.004 per g/dL). The frequency with which cases of current smokers was significantly higher than that of controls (odds ratio: 3.475). The above parameters of cases compared with controls were statistically significant after adjustments for age, sex, and history of hypertension. Low albumin levels and smoking in addition to hypertension are significantly associated with aortic dissection.