Sixty-nine patients with endoscopically diagnosed duodenal ulcer were randomised to either Group I or Group II. Group I patients (n = 35) received tablet ranitidine 150 mg twice daily along with tablet aspirin 600 mg three times a day while Group II patients received only tablet ranitidine 150 mg twice daily. Eight patients (four in each group) dropped out of the trial but were included in the final analysis as failure of treatment. At the end of four weeks 51.4% ulcers healed in Group I compared to 58.8% in Group II. The difference between the two groups was not significant. There was also no statistical difference in the time required for relief of pain, number of patients relieved of pain and the complication rate. It is concluded that aspirin concurrently administered with ranitidine is safe and does not delay the healing of uncomplicated duodenal ulcers.