Abstract. Objective: To compare the efficacy of droperidol with that of prochlorperazine for the treatment of benign headaches in emergency department (ED) patients. Methods: Prospective, randomized clinical trial in an urban ED. Patients were given either droperidol, 5 mg intramuscular (IM) or 2.5 mg intravenous (IV), or prochlorperazine, 10 mg IM or 10 mg IV. Measurements included side effects and the patient's pain perception as measured on a 100-mm visual analog scale (VAS) at baseline, 30, and 60 minutes after the medication was given. Data were analyzed using chi-square, two-tailed t-tests, and two-way analysis of variance (ANOVA) when appropriate. Results: During an eight-month period, 168 patients were enrolled. Eighty-two (48.8%) of the patients received droperidol; 86 (51.2%) received prochlorperazine. In the droperidol group, 49 (59.6%) received IM adminstration and 33 (40.4%) IV. In the prochlorperazine group, 57 (66.3%) received IM administration and 29 (33.7%) IV. Sixty minutes after the medication, the mean decrease in the VAS scores was 81.4% for droperidol and 66.9% for prochlorperazine (p = 0.001). At 30 minutes, 60.9% of the patients receiving droperidol and 44.2% of the patients receiving prochlorperazine had obtained at least a 50% reduction in their VAS scores (p = 0.09). At 60 minutes, 90.2% of the patients receiving droperidol and 68.6% of the patients receiving prochlorperazine had at least a 50% reduction in their VAS scores (p = 0.017). No difference between IM dosing and IV dosing was detected. Side effects, including dystonia, akathisia, and decreased level of consciousness, were seen in 15.2% of the patients receiving droperidol and 9.61% of the patients receiving prochlorperazine. No significant or persisting morbidity was detected. Conclusions: Droperidol was more effective than prochlorperazine in relieving pain associated with benign headaches.