Inflight medical incapacitations are rare events that can result in the loss of lives and aircraft. The potential for an in-flight medical event deserves the attention of certification authorities. Cardiac emergencies are among the most common serious events. The primary focus of this study was to examine whether the proportions of pilots with reported cardiac conditions could be used to identify those who had inflight medical incapacitations.The Civil Aerospace Medical Institute Inflight Incapacitation Registry was searched to identify airline pilots with a cardiac history and an inflight medical event between 1995 and 2015. The Federal Aviation Administration's Decision Support System was searched for airline pilots without an inflight medical event. The cardiovascular history of incapacitated pilots was then compared to that of airline pilots without incapacitation events.Although a significantly greater proportion of airline pilots with cardiac events had pacemakers than a control group with the same cardiac history who did not have inflight events, no significant difference was found in the proportions of other markers of cardiac health.The proportions of airline pilots with identified cardiac conditions could not be reliably used to identify which pilots had inflight incapacitations.DeJohn CA, Mills WD, Hathaway W, Larcher J. Cardiac inflight incapacitations of U.S. airline pilots: 1995-2015. Aerosp Med Hum Perform 2018; 89(9):837-841.