The goals of this study were to compare whether emergency department (ED) patients' pain intensity (PI) is measured differently by male and female nurses and to determine whether PI, heart rate (HR), and respiratory rate (RR) were used to prioritize patient urgency differently by male and female nurses. The associations between patients' PI|HR|RR and the Emergency Severity Index (ESI) scores they were assigned by attending nurses were analyzed using a national database of electronic medical records of US Veterans Affairs ED patients from 2008 to 2012. A total of 129,991 patients presenting for emergency care (Mage = 59.5, 92% males) and their triage nurses (n = 774, Mage = 47.5, 18% males) were analyzed, resulting in a total of 359,642 patient–provider interactions. Patients' PI did not differ by the nurse's gender; however a cross-classified mixed-effects model showed that nurse gender influenced how PI and RR measurements informed the ESI levels that male patients received. Higher PI levels were associated with more urgent (higher priority) ESI levels by female nurses, yet less urgent ESI levels by male nurses. In contrast, male patients with high RR received more urgent ESI levels by male nurses, whereas the nurse gender did not influence ESI assignments for female patients. These findings show that ED patients receive disparate treatment based on inherent characteristics of their triage nurses, and more standardized (eg, automated) protocols that can account for implicit social factors on health care practice for reliably assessing and prioritizing ED patients may be currently warranted.