Many clinical trials on the effects of H2-antagonist drugs on reflux oesophagitis have shown unsatisfactory healing rates after conventional therapy, i.e. 4 to 12-week administration of 400 or 150mg bd of cimetidine or ranitidine, respectively. In order to verify if longer periods of treatment and/or higher dosage of drug can increase the healing rate, we performed a single-center double blind trial of 12 to 24 week duration on 75 patients with erosive/ulcerative reflux oesophagitis, comparing two ranitidine regimens, 150 vs 300mg bd. Patients who were healed after this period entered a 12 month maintenance treatment with half the dose previously received, i.e. 150 vs 300mg at bedtime. Our results show that, with both dosages, prolongation of acute treatment from 12 to 24 weeks allows complete additional healing of almost one fourth of patients. Furthermore, the data show that, both in the short and long-term treatment of reflux oesophagitis, conventional doses of ranitidine are as effective as double doses.