Summary:We describe the clinical features and therapeutic outcome in 49 patients in whom benign gastric ulceration of an hiatal hernia was demonstrated endoscopicaily. Hiatal hernial ulcers accounted for 10% of all benign gastric ulcers. The typical patient was an elderly female with a history of dyspepsia who was receiving non-steroidal anti-inflammatory drugs. Twenty-seven (55%) patients had evidence of haemorrhage (acute in 15; chronic in 12) from the hiatal hernial ulcer at presentation. In 16 (33%) patients, symptoms attributable to haemorrhage constituted the sole clinical evidence of the hiatal hernial ulcer. Acute haemorrhage from hiatal hernial ulcers was associated with non-steroidal anti-inflammatory drug (NSAID) treatment (P < 0.05). Chronic blood loss from hiatal hernial ulcers was associated with female gender (P < 0.005) but not with NSAID treatment.Hiatal hernial ulcers healed slowly in response to medical treatment with H2-receptor antagonists (median time to healing 12 weeks). Surgical treatment may be the therapy of choice for hiatal hernial ulcers because of the high complication rate, poor response to medical therapy, and the apparent predominance of mechanical aetiological factors.