A double-blind controlled trial was carried out in 37 patients with oesophagitis, confirmed endoscopically and histologically, to compare the efficacy of treatment with a carbenoxolone/alginate antaacid combination with that of the alginate antacid compound used alone. The total daily dosage of carbenoxolone was 100 mg. During the 8-week-period of the trial patients were seen every 2 weeks and endoscoped at 4 and 8 weeks. Response to treatment was assessed symptomatically and endoscopically using 6-point grading scales, and multiple oesophageal biopsies were taken at each endoscopy. The addition of carbenoxolone to the alginate antacid compound was shown to enhance symptomatic relief and to increase healing of oesophagitis and oesophageal ulceration significantly. No serious side-effects were reported in either group. Although there were a number of biochemical or clinical abnormalities recorded, none required any alteration in treatment.