Eighteen opossums received 2250 rad 60Co to the entire esophagus and lower esophageal sphincter. Animals received treatment with 600 mg aspirin, 25 mg/kg hydrocortisone, or saline before irradiation and twice daily for 1 week after irradiation. At 10 days postirradiation, animals were evaluated for signs of acute esophagitis by esophagoscopy and barium esophagram. Each animal was then killed and the esophagus removed and evaluated histologically. Animals treated with either aspirin or hydrocortisone had significantly milder esophagitis than control irradiated animals.