Background: Traumatic brain injury (TBI) patients are highly susceptible to secondary insults to the injured brain (e.g., hypoxia, hypotension, hyperthermia, hypothermia, and hyperglycemia). Patients with secondary insults have been shown to have worse outcomes. Over one third of the patients transported by Critical Care Air Transport Teams (CCATT) have had TBIs. Considering CCATT patients travel thousands of miles, pass through multiple hospital systems, and are exposed to the stresses of flight on military cargo aircraft, the occurrence and timing of secondary insults need to be explored. Purpose: This study describes the occurrence of secondary insults in isolated TBI patients transported by CCATTs from the point of injury to arrival in the United States between 2001 and 2006. Methods: A descriptive retrospective cohort design was used to conduct a secondary analysis of 64 CCATT patients with isolated TBI from the Wartime Critical Care Air Transport Database. Data elements in the database were abstracted from existing records including theater evacuation and trauma registry systems, transport documents, flow sheets, and hospital medical records. Results: The median days from the point of injury to patients arriving in Germany and in the United States decreased from 2.5 to 1 day and 8 to 3.5 days respectively. Over half of the study participants had at least one documented episode of a secondary insult. Hyperthermia was the most common secondary insult with the occurrence rate increasing from the point of injury to arrival in the United States. No significant difference in the documented occurrence of secondary insults was found between type of aircraft used for CCATT transport even with a change in primary aircraft. Finally, no significant difference in the documented occurrence of secondary insults was found by year of occurrence. Conclusion: Despite the limitations of missing data, secondary insults were common and should be targeted for prevention to optimize outcomes. The use of opportune cargo aircraft by CCATTs to transport patients is supported. The decision to transport patients earlier before they are stabilized is also supported. Additional studies with more complete data and detailed outcome measures are warranted.