Survivor syndrome (also KZ syndrome) is a phrase which has been used to describe the set of shared reactions and behaviors of people who have survived a massive and adverse event, such as the Holocaust in Nazi Germany. Many survivors of the death camps have developed post-traumatic stress disorder.

People with survivor syndrome may also have been victims, played a part in, or feel emotionally tied, to a catastrophic event such as a war, a genocide, or a natural disaster. Someone who witnessed and survived such an event may have survivor syndrome, and also may feel guilty that they survived the trauma and others - such as family, friends, and colleagues - did not.