Objective We examined associations between emotional exhaustion and selected sociodemographic and psychological factors among nurses in inpatient and outpatient nursing units at a university hospital in South Korea. Methods The participants were 386 nurses who completed the Maslach Burnout Inventory, a measure of emotional exhaustion. Psychological characteristics were evaluated, including hardiness, self-esteem, experience of trauma, resilience, perceived stress, and social support. Correlation analyses examined the relationships between emotional exhaustion with sociodemographic, occupational, and psychological characteristics. Linear regression was used to evaluate the associations between emotional exhaustion and the assessed characteristics. Results Higher emotional exhaustion scores were associated with greater depression, anxiety, traumatic experience, and perceived stress. Exhaustion was inversely associated with hardiness, self-esteem, resilience, and quality of life. The regression analysis indicated that gender, marriage, resilience, depression, perceived stress, and secondary traumatic stress were significantly associated with emotional exhaustion. Conclusion This study showed that psychological characteristics, such as resilience, depression, and secondary traumatic experiences, may cause emotional exhaustion. Understanding the needs of people with distinct demographic and psychological characteristics offers valuable direction for the development of intervention programs to prevent burnout among nurses.