Background To ensure the rapid and correct triage of patients in potential need of specialized treatment, Norwegian hospitals are expected to establish trauma teams with predefined criteria for their activation. The objective of this study was to map and describe the criteria currently in use. Methods We undertook a cross-sectional survey in the summer of 2008, using structured telephone interviews to all Norwegian hospitals that might admit severely injured patients. Results Forty-nine hospitals were included, of which 48 (98%) had a trauma team and 20 had a hospital-based trauma registry. Criteria for trauma team activation were found at 46 (94%) hospitals. No single criterion was common to all hospitals. The median number of criteria per hospital was 23 (range 8-40), with a total number of 156 and wide variation with respect to physiological "cut-off" values. The mechanism of injury was commonly in use despite a well-known, large over-triage rate. Conclusions In recent years, Norwegian hospitals have gradually established trauma teams and criteria for their activation. These criteria show considerable variation, including physiological "cut-off" values.