At the intensive care station of the Internal Medicine Department, University Clinic Graz, all patients admitted were promptly and carefully examined in case of suspected acute intrathoracic aortic dissection and immediately treated. In 1987 a total of 4446 patients were referred to this CCU, 893 suffered from acute thoracic pain. In 21 patients of the latter a clinical suspicion of aortic dissection was observed. In 9 patients of these, diagnosis could be established within 5 hours by echocardiography, CT and angiography. 11 patients had no dissection while one positive finding could only be determined by postmortem exam. Retrospectively, these figures for 1982 were 3908 admitted patients, 790 suffering from acute thoracic pain of which only 5 showed suspected dissection. In 3 cases dissection could be confirmed using the same diagnostic procedures, but 2 were without finding. Further 3 patients out of the total series were affected with dissection which could only be determined postmortem. Out of the 9 patients with positive diagnosis, 6 showed Typ I, 1 Typ II and 2 Typ III dissection according to DeBakey (8m, 1f, range 46-78 years). 2 patients underwent surgery immediately after diagnosis, 1 after 12 hours, while 4 cases were conservatively treated. These 7 patients have survived by controlled hypotension up to now (10 to 22 months). Two patients died 2 and 10 hours, respectively, after admission with positive diagnosis. In spite of the severity of this disease prompt and efficient diagnosis and rapid therapeutic management are the key to survival.