Based on its roots in military air evacuation, helicopter emergency medical services (HEMS) has always been emphasized as a tool for trauma transportation. Despite much discussion regarding resource allocation for HEMS, a literature search found little recent systematic review of pertinent studies. As HEMS utilization is subject to increased scrutiny in a health care dollar-conscious environment, it was felt that a compendium of available outcomes-related literature could assist those assessing utility of HEMS trauma transport. The current study utilized a Medline search to identify outcomes studies relative to HEMS trauma transport. The goal of this review is to provide a useful resource for those interested in pursuing systematic review of the HEMS trauma outcomes literature. The primary purpose of the review is bibliographic, but there is editorial comment after each paper's summary. The initial article in this two-part series focused on HEMS outcomes literature covering noninjured patients as well as papers assessing outcome in mixed trauma-nontrauma HEMS study groups.