Of 1000 patients with hiatal hernias, 45 had biopsy-proved columnar-lined esophagus (CLE). Twenty-one were male and 24 female, with bimodal age ranges peaking at 0-10 and 48-80 yr. Of the 1st decade patients, all boys, 2 were brothers. While 44 had dysphagia, 113 also had iron-deficiency anemia. All had X-ray-proved sliding hiatal hernias, with esophageal stricturing at the squamous cell-columnar cell interface. In 43 cases this area was 35 cm or less from the upper jaw. The epithelial histology showed simple, tubular, mucus-secreting glands (45 cases), goblet cells (7 cases), no goblet cells (38 cases) and gastric-type epithelium with parietal cells (19 cases). In 2 cases CLE was rising up the esophagus from 35-30 cm in 3 yr and from 40-23 cm in 10 yr. No stricture became neoplastic. Clinical evidence supports the view that CLE has a double etiology: It is congenital in children but acquired, akin to intestinalization of the stomach, in adults with sliding hiatal hernias; in the latter instance, CLE occurs as an alternative end-point to reflux esophagitis. Treatments and long-term results are discussed. All patients had initial stricture dilatation with biopsy. In 17 this was the sole treatment. In 16 cases a latter transthoracic herniorrhaphy was performed to reduce the hiatal hernia and prevent further stricturing. Fifteen patients had transmural strictures. For this group, our experience with Roux-Y esophagogastrostomy and esophagojejunogastrostomy, with stricture excision and also with mere bypass of the stricture is stated. For the young, after stricture excision, eosophagojejunogastrostomy with pyloroplasty, performed in the 2nd decade, is favored. In the elderly, especially after unsuccessful hiatal herniorrhaphy, eosophagojejunogastrostomy with stricture bypass proved satisfactory 3 yr after the operation.