This article explores secondary traumatic stress (STS) and the emotional challenges that emergency nurses face when dealing with traumatised patients. The few studies on STS have shown a higher occurrence of STS symptoms in emergency nurses but provide limited evidence on how personal experiences may contribute to STS. Risk factors identified include repeated exposure to trauma; morbidity and mortality; personal trauma; chronic stressors; workload and emergency department pressures. STS can lead to reduced job satisfaction, sick leave and burnout. Protective factors include awareness and self-care, emotional intelligence, social support and education about STS. Strategies to minimise STS include balancing personal and professional life and the support of employers to help reduce compassion fatigue and aid staff retention.