Introduction: Optimal nutritional support is becoming increasingly important in Emergency Departments (EDs) as over half of patients presenting to ED are reported to be malnourished or at risk of malnutrition. Few studies have examined the barriers and facilitators to nutritional support in ED. Aim: To identify barriers and facilitators to providing optimal nutritional support in the ED from nurse and physician perspectives. Methods: A cross-sectional 31-item electronic survey was developed, validated, and distributed nationally in August 2021 in China. Results: A total of 1766 eligible respondents completed the survey, including 846 ED nurses and 920 ED physicians from 155 hospitals. Barriers to optimal nutrition were moderate (2.72/5 ± 0.88); the most common barrier was lack of multidisciplinary team-work support. Facilitators to support optimal nutrition were moderately high (3.58/5 ± 1.08); the most common facilitator was technical/professional support and organizational management. Respondents who received recent nutrition training and those with higher levels of nutrition knowledge (self-rated) perceived fewer barriers overall to optimal nutrition in ED (P < 0.01). Conclusion: Context specific barriers and facilitators both hinder and support optimal nutrition in ED. Further research is required to develop tailored interventions to address specific barriers to optimal nutrition and enhance facilitators in the ED context.