Background:This randomized, clinical trial evaluates the analgesic and safety of paracetamol and Morphine in management of headache.Objectives:This study aimed to evaluate the analgesic and safety effects of intravenous single dose of paracetamol, versus morphine in post trauma headache in emergency departments.Patients and Methods:This study was a single-center, prospective, randomized, double-blind clinical trial conducted on two groups treated with intravenous paracetamol and intravenous morphine. Thirty patients were enrolled in each group. Patients (18-55 years-old adults) complaining from headaches due to pure trauma were included in the study. The inclusion criteria required patients to have headachesof more than 40 mm on a 100 mm visual analogue scale without any pathological findings in their clinical examinations and imaging studies.Results:Mean duration required to treat the headache was 37.43 and 71.93 minutes in the groups administered paracetamol (group A) and morphine (group B), respectively. After 15 minutes of treatment, this changed to 31.7 ± 18.0 mm (95% CI 8.2 to 25.2) and 48.3 ± 14.1 mm (95% CI 8.2 to 25.2) in groups A and B, respectively. Headache of the patients of group A significantly mitigated in comparison with group B (P < 0.005). Headache of group Apatients was significantly mitigated 30 minutes after treatment (P < 0.005).Conclusions:Intravenous paracetamol is an effective and safe treatment for patients admitted to the emergency department with headaches caused by head trauma.