Background: Dry cough is the most common adverse effect and limiting factor of all angiotensin converting-enzyme inhibitors (ACEIs). Prostaglandins have been pinpointed as playing an important role in the genesis of this problem. This double blind clinical trial desinged to study the efficacy of 500 milligram (mg) of aspirin comparing with placebo in controlling Enalapril-induced cough. Methods: The subjects were 32 patients who had developed Enalapril-induced cough. They were randomized into two groups: a group of daily dose of aspirin, 500 mg and a group of placebo for a treatment period of 4 weeks. Mean of cough severity was compared between two groups before treatment and weekly, until 4 weeks. Results: Mean of cough severity in aspirin and placebo groups before and at the end of first week of treatment did not show any significant difference. After the second, third, and fourth weeks, cough severity scores were significantly reduced in aspirin group (p<0.001). Conclusion: 500mg aspirin, once daily, can suppress or abolish Enalapril-induced cough and this finding proposes alternative therapeutic approach for ACEIs-induced related cough.