Although type B aortic dissection has been treated with beta blockers to lower the arterial blood pressure (BP), there has been little evidences about reduction in heart rate (HR). We assessed whether tight HR control improved the outcome of medical treatment in patients with aortic dissection. From 1997 to 2005, 171 patients with acute aortic dissection medically treated and controlled to lower BP under 120 mm Hg were enrolled. Based on the average HR at 3, 5, and 7 days after the onset, patients were divided into tight HR (<60 beat per minute) control group (32 patients; mean HR of 56.6+/-3.1 beat per minute) and conventional HR (>/=60 beat per minute) control group (139 patients; mean HR of 71.7+/-8.2 beat per minute). We compared the frequency of aortic events including late organ or limb ischemia, aortic rupture, recurrent dissection, and aortic expansion of >5 mm, and surgical requirement between two groups. During a median follow-up of 27.0 months, late organ or limb ischemia, aortic rupture, recurrent dissection, pathological aortic expansion, and aortic surgery occurred in 0, 8, 14, 39, and 26 patients, respectively. Reduction in aortic events was observed in tight HR control group (12.5%) compared to conventional HR control group (36.0%), (Odds ratio: 0.25, C.I.: 0.08 to 0.77, P<0.01). The present study demonstrated that tight heart rate control improved the outcome of medical treatment in patients with aortic dissection.