To explore and describe workplace stress levels and health-promoting behaviours reported by emergency nurses in China, and to investigate factors associated with workplace stress and health-promoting lifestyle behaviours among emergency nurses. A cross-sectional study was conducted between October 2019 and January 2020. Nurses (n = 1565) were recruited from the emergency departments of 54 hospitals within the Sichuan Province of West China. Each subject completed the Chinese versions of the Nurse Workplace Stress Scale, the Health-Promoting Lifestyle Profile (HPLP-II) and demographic questions. Linear regression analyses were used to identify associations between workplace stress and the health-promoting lifestyle and risk factors correlated with these two measurements. Workplace stress was negatively associated with health-promoting behaviours. Linear regression analysis showed that gender, marital status, whether wages met expected standards and professional rank were found to be associated with health promotion behaviours; marital status, whether income met expected standards, the number of night shifts per month and health promotion behaviours were found to be associated with workplace stress. Higher levels of workplace stress are associated with lower levels of engagement in health-promoting behaviours, suggesting the potential for reducing workplace stress through the adoption of healthier habits. Policies should prioritize workplace stress by promoting healthy lifestyle initiatives.