Omeprazole is more effective than the histamine H2-receptor antagonists cimetidine and ranitidine in producing rapid relief of symptoms and healing of reflux oesophagitis. The analyses presented in this paper show that omeprazole is also more cost-effective, whether the end-point is endoscopically confirmed oesophageal healing, symptom relief, or both. On the basis of published trial data, a protocol approach to treating reflux oesophagitis with ranitidine, cimetidine and omeprazole has been constructed and costed. Symptom relief with omeprazole is a better indicator of mucosal healing than with ranitidine. The effect of initial endoscopic grading of mucosal damage on the subsequent healing provided by the acid pump inhibitor or the histamine H2-receptor antagonists is examined.