Trauma care is an example of dynamic, complex, and safety-critical teamwork. The staff in trauma centers works under time pressure and lacks effective information technologies to support teamwork and reduce errors. This work presents a qualitative study that looked at the teamwork errors and their causes to better understand the challenges in providing computerized support for this user group. Keywords Teamwork, human errors, healthcare, trauma ACM Classification Keywords H.5.3 [Group and Organization Interfaces]: Computersupported cooperative work.