This study investigates if perceived self-efficacy during an emergency situation has a protective role in the development of posttraumatic stress symptoms among Italian and Spanish survivors of several emergency situations. We explored the impact of self-efficacy in a multiple regression model including other predictors of posttraumatic stress symptoms, such as emergency prevention knowledge; trust in emergency services; risk perception of becoming a victim of an emergency situation; and conscious and active behaviors in comparison with no conscious and no active behavior during the emergency. We carried out a retrospective study recruiting 214 participants who reported their experience as victims of one specific emergency event. Results showed that survivors who perceived themselves as more self-efficacious during the traumatic event had less posttraumatic stress symptoms. In contrast, female gender, more self-threat perception and higher trauma severity were associated with more symptoms. Findings contribute to better understand human behavior in emergency situations and evidence the protective role of perceived self-efficacy beliefs among survivors of emergency situations.