Drug-induced oesophageal lesions have attracted increasing attention during the past few years. A test model is presented for assessing irritative or ulcerogenic effects of potential drugs on the oesophagus. In this model the pig oesophagus is used, as it is more similar to the human oesophagus than models used in other techniques that have been suggested. The beta-blockers, alprenolol and propranolol, displayed the same ulcerogenic properties with this test model as reported with other test models in the literature. The beta 1-selective blocker metoprolol, did not have such ulcerogenic effects. The pig model is suggested as the method of choice in evaluating the potential irritative or ulcerogenic effects of pharmaceutical formulations intended for human use.