The need for interhospital patient transfer after mass casualties may be a consequence of triage errors. Indications for interhospital patient transfer following seven suicidal bus bombings in Israel were reviewed to identify possible errors in triage at the scene. Medical records of victims arriving to hospitals were analyzed for age, injury description, Injury Severity Score (ISS), and indication and destination of interhospital transfer. A total of 473 victims were involved, 74 of whom died at the scene (15.6%). Mean victim age was 29 ± 16 (SD) years. Interhospital transfer was necessary for 29 patients. Indications for transfer included (1) mandatory lifesaving procedures en route to trauma center (n = 14), (2) underdiagnosis at the scene (n = 1), (3) insufficient local resources (n = 9), and (4) triage-related errors (n = 5). The ratio between interhospital transfer due to triage errors and the victim population who may need to be transferred is suggested as quality assurance (QA/QI) indicator for triage.