Emergency department (ED) use has increased disproportionately for pediatric psychiatric care. This study aimed to identify predictors of ED use within 30 days of discharge from a pediatric psychiatric hospitalization.ED use was assessed in the 30 days after discharge. Univariate logistic regression modeling identified predictors of ED use, which were used in subsequent multivariate modeling.Greater number of trauma types (odds ratio [OR]=1.92, 95% confidence interval [CI]=1.50-2.45, z=2.67, p=0.008), generalized anxiety disorder (OR=3.20, 95% CI=1.78-5.76, z=1.98, p=.048), and longer length of stay (OR=1.05, 95% CI=1.03-1.07, z=2.74, p=0.006) were associated with increased ED use within 30 days of discharge.ED use may be an important marker of negative outcomes within 30 days of discharge from pediatric psychiatric hospitalization. Patients with high trauma exposure, anxiety, and acuity marked by increased length of stay may require additional services to prevent unplanned ED use for psychiatric crises.