Background: Optimal care of multiple trauma patients has to be at a high level around the clock. Trauma care algorithms and guidelines are available, yet it remains unclear if the time of admission to the trauma room affects the quality of care and outcomes. Hence the present study intends to compare the quality of trauma room care of multiple severely injured patients at a level-1 trauma center depending on the time of admission. Methods: A total of 394 multiple trauma patients with an ISS >= 16 were included into this study (observation period: 52 months). Patients were grouped by the time and date of their admission to the trauma room [business hours (BH): weekdays from 8: 00 a. m. to 4: 00 p. m. vs. non-business hours (NBH): outside BH]. The study analysed differences in patient demographics, trauma room treatment and outcome. Results: The study sample was comparable in all basic characteristics [mean ISS: 32.3 +/- 14.3 (BH) vs. 32.6 +/- 14.4 (NBH), p = 0.853; mean age: 40.8 +/- 21.0 (BH) vs. 37.7 +/- 20.2 years (NBH), p = 0.278]. Similar values were found for the time needed for single interventions, like arterial access [4.8 +/- 3.9 min (BH) vs. 4.9 +/- 3.4 min (NBH), p = 0.496] and quality-assessment parameters, like time until CT [28.5 +/- 18.7 min (BH), vs. 27.3 +/- 9.5) min (NBH), p = 0.637]. There was no difference for the 24 h mortality and overall hospital mortality in BH and NBH, with 13.5% vs. 9.1% (p = 0.206) and, 21.9% vs. 15.4% (p = 0.144), respectively. The Glasgow Outcome Scale (GOS) comparison revealed no difference [3.7 +/- 1.6 (BH) vs. 3.9 +/- 1.5 (NBH), p = 0.305]. In general, the observed demographic, injury severity, care quality and outcome parameters revealed no significant difference between the two time periods BH and NBH. Conclusions: The study hospital provides multiple trauma patient care at comparable quality irrespective of time of admission to the trauma room. These results might be attributable to the standardization of the treatment process using established principles, algorithms and guidelines as well as to the resources available in a level-1 trauma center.