Recent literature has called attention to an esophageal motor abnormality characterized by high amplitude peristaltic contractions (HAPC). We characterized symptoms, manometric characteristics, and radiographic findings of 19 such patients and compared them to patients with other nonspecific esophageal motor disorders (NEMD). In the HAPC group, mean amplitude was 254 +/- 14 mm Hg, which was significantly higher than that of control subjects (94 +/- 8.9 mm Hg) and of those with other NEMD (116 +/- 10.8 mm Hg). Contractile duration of the HAPC and NEMD groups was 6.9 +/- 0.5 sec and 5.9 +/- 0.4 sec, respectively, both being significantly higher than normal. Results of esophagograms were frequently abnormal in both groups, but there was no specific abnormality separating the two groups. There was a high incidence of chest pain and dysphagia in the HAPC group. These data suggest that HAPC may represent a distinct subgroup of primary esophageal motor disorders.