This study aimed to evaluate the effectiveness of nurse practitioner service on key emergency department indicators. A pragmatic randomized controlled trial was conducted. Patients were randomly assigned to standard emergency department care or nurse practitioner care. The outcome measures reported were comparisons on key service indicators. There were 260 patients enrolled in the study, 128 receiving standard emergency department medical care and 130 receiving nurse practitioner care. There were no significant differences between the 2 groups regarding waiting times, length of stay, numbers of patients who left, patient representations within 48 hours, and the use of evidence-based guidelines.