OBJECTIVES To compare the medical treatment of chronic type B aortic dissection with beta-blockers versus other antihypertensive treatments in terms of their requirement for surgical intervention and treatment costs. METHODS Case records of the 130 patients treated for aortic dissection type B in this unit between 1988 and 1997 were reviewed. Seventy-eight of 130 patients with chronic dissection have received isolated medical treatment. Seventy-one of 78 patients were discharged alive. Fifty-one of 71 received beta-blocker treatment, 20/71 were treated with other antihypertensive drugs. RESULTS Surgery for aortic dissection became necessary in 20/71 patients (28%) during follow-up (mean, 4.2 years): 10/51 in the beta-blocker group and 9/20 in the other antihypertensive drug group. The freedom from subsequent aortic operation was 80 and 47%, respectively (P=0.001). Indications for emergency surgery were increased aortic diameter (79%), symptomatic aortic aneurysm (11%), and renal artery hypoperfusion (5%). The median hospitalization time during follow-up (dissection-related) was 2 days for patients who received beta-blockers and 16 days for patients who received other antihypertensive drug treatments (P=0.001). The cost of treatment/patient per year amounted to 644 and 12748 euros, respectively. CONCLUSIONS A substantial proportion of patients with chronic type B dissection who receive initial medical management will later need surgery. Long-term treatment with beta-blockers reduces the progression of aortic dilatation, the incidence of subsequent hospital admissions, as well as the incidence of late dissection-related aortic procedures and the cost of treatment. Patients with chronic type B dissection need, in addition to frequent follow-up of aortic diameter, continuous treatment with beta-blocking agents.