The reliability of military and civilian preventable death studies is hindered by inconsistent definitions, incompatible criteria, and the overall heterogeneity in study methods. The complexity, inconsistency, and unpredictability of combat require unique considerations to perform a methodologically sound combat-related preventable death review. As the Department of Defense begins the process of developing recommended guidelines and standard operating procedures for performing military preventable death reviews, consideration must be given to the factors known to increase the risk of bias and poor reliability.