This study examined the necessity for an intensive care environment after abdominal aortic surgery. The detailed records of 45 consecutive patients were reviewed for the first 48 h after operation, recording the occurrence and numbers of episodes of defined medical events or prescription of non-routine drugs. Medical events were hypertension (greater than 200 mmHg), hypotension (less than 100 mmHg), obliguria (less than 20 ml/h) and pulmonary problems. Thirty-six patients (80%) had medical events (hypertension 20, hypotension 17, oliguria 31, hypoxia 10, chest complications 12), and 38 (84%) had medical interventions. Only two had no events or interventions. Twenty-seven (59%) had more than one episode of a medical event which would not have been predicated from their preoperative state. There were three deaths (mortality 6.7%). These results support the case for intensive monitoring and immediate access to experienced medical advice for these patients. In hospitals where the intensive care unit is the best place to provide these facilities, elective operation may need to be deferred if an intensive care bed is not available.