There were significant differences in the time taken to resuscitate 257 trauma patients from four internationally recognized trauma centres. The fastest unit completed resuscitation in 15 min while the slowest took 105 min. This variation was not explained by differences in the type of patient dealt with, seniority of the team leader, or the number of personnel in the trauma team. Although there were significant differences between the units with regard to these parameters, they did not account for the resuscitation time variations. The average post-qualification time of the team leader at the fastest unit was 2 years. Although the slowest unit had the smallest trauma team (two people), larger numbers of personnel did not shorten resuscitation times. The time taken to carry out the ABC of the primary survey was significantly correlated with patient's physiological change in the resuscitation room (R = -0.63, P less than 0.0001 with systolic blood pressure; R = -0.68, P less than 0.01 with the revised trauma score). A multiple regression with survival as the dependent variable revealed that this time was also a predictor of the patient's eventual outcome (t = 3.18, P less than 0.005).