Introduction: This study aimed to evaluate the clinical efficacy of intravenous metoclopramide for the relief of pain and nausea among the emergency department patients with renal colic: Methods: Patients were randomised into three groups: tenoxicam (20 mg); tenoxicam (10 mg) plus metoclopramide (10 mg); and metoclopramide (10 mg). Changes in pain and nausea were examined at the 10th, 20th and 30th minute after treatment. The development of side effects would be recorded. After the 30th minute, the need for additional pain and nausea relief was evaluated. Results: Totally 80 patients were enrolled in each group. There was significant mean pain score difference as measured by visual analog scale (VAS) from 0 minute to 10th, 20th and 30th minute post-treatment for all treatment groups (p<0.001). There was no significant difference in mean VAS decrease from 0 minute to the 30th minute: tenoxicam group: 36 mm [95% confidence interval (CI) 28-43 mm] vs. tenoxicam plus metoclopramide: 45 mm (95% CI 38-52 mm) vs. metoclopramide group: 37 mm (95% CI 30-45 mm) (p=0.163). Similarly, no significant differences in mean nausea scores between the three groups were demonstrated at the 10th, 20th and 30th minute after treatment (p=0.236, 0.330 and 0.652 respectively). After the 30th minute, 43 (53%) patients needed additional pain relieving agent in the tenoxicam group compared to 27 (33%) patients in the tenoxicam-metoclopramide group and 33 (41%) patients in the metoclopramide group (p=0.030). No significant adverse drug reaction events were encountered. Conclusion: Metoclopramide is as effective as tenoxicam to treat pain and nausea for patients with renal colic in the emergency department.