Background: Trauma in the head is one of the most common childhood injuries. Children with minor head trauma are at higher risk of intracranial injury (ICI). Vomiting is one of the most common signs after minor head trauma in children, and different treatments are suggested for managing it. Objective: To determine the antiemetic effects of dexamethasone in children with minor head trauma. Methods: This single blind randomized clinical trial study was carried out during the period from September 2015 to August 2016 in Imam Khomeini and Golestan Hospitals in Ahvaz, Iran, on 64 children (2-8 years old) with minor head trauma (Minor head trauma was considered as GCS 14-15) who were admitted to the hospitals' emergency departments. In the intervention group, metoclopramide (0.15 mg/kg) and dexamethasone (0.15 mg/kg) were injected. In the placebo group, patients received metoclopramide (0.15 mg/kg) and placebo. Nausea severity was measured using Rhodes Index of Nausea and Vomiting. The data were analyzed using SPSS version 19. We used descriptive statistics, Chi-squared, t-test, and ANOVA for the analyses of the data. P-value of less than 0.05 was defined as the level of significance. Results: Finally, 62 patients (mean age of 56.4 and 62% male gender) attended the study and were equally divided into intervention and placebo groups. The Rhodes Index of Nausea and Vomiting on the intervention and placebo groups was 4.9±3.73 and 7.19±3.79, respectively (p=0.021). Conclusion: Collectively, our results indicated that dexamethasone can be used as an effective medication along with metoclopramide to control vomiting in children with minor head trauma. Trial registration: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2016081128944N1.