Prospective evaluation of 103 consecutive transports for diagnostic studies of 56 patients out of the Shock Trauma Unit over a 3-month period was done to document physiologic changes, the cost of each transport, and to assess whether the information gained was utilized to change patient management. Of the 56 patients, 36 (65%) were males and 20 (35%) were females with an age range of 14–82 years (mean, 48 years). The Apache II score ranged from 3–49 (mean, 19.4). There were seven types of diagnostic studies: CT of the head (28), CT of abdomen (35), CT of chest (four), angiography (nine), ventilation/perfusion scan (three), tomography (seven) and miscellaneous studies (15). The average trip time was 81 minutes, a range of 15–210, requiring an average of 3.3 personnel per trip. Ninety-four transported patients had ventilatory support, 26 had PA lines, and 26 transports required three or more IV infusion pumps. Sixty-eight per cent of all transports experienced serious physiologic changes of 5 minutes' duration defined as BP systolic or diastolic $pM 20 mm Hg (40%), pulse $pM 20 beats/minute (21%), ventilatory rate $pM5/minute (20%), O2 saturation decrease by 5% or more (17%). There was a total of 113 serious changes requiring an increase in support of the patient during the transport. There were no significant differences when comparing diagnosis of patient or types of studies to the number of changes in the physiologic parameters, nor were there significant differences within a physiologic parameter when comparing patient types or diagnostic studies. Twenty-five of the transports resulted in a change in patient management within 48 hours. However, no diagnostic study produced a significantly greater number of management changes. The average transport cost per patient was $465.00. Transportation of patients from the ICU resulted in a large number of physiologic changes, each requiring changes in support, therefore suggesting a need for the preservation of equally intensive monitoring and care of these patients during transports. The indications for diagnostic studies must be weighed against a 76% chance that the result will not alter the patient's management.