Background: The position of the gastroesophageal junction is maintained by a complex of fibroelastic ligaments. The purpose of this study was to characterize and compare the histology of these ligaments in patients with gastroesophageal reflux disease (GERD) and hiatal hernia (HH) versus GERD alone, with emphasis on the elastin morphology. Study Design: Thirteen patients were examined at the time of laparoscopic fundoplication for symptomatic GERD; nine had no significant HH and four had large diaphragmatic hernias (GERD/HH). Tissue biopsies were obtained from the gastrohepatic ligament (GHL, n = 5 and n = 3, GERD and GERD/HH, respectively), the phrenoesophageal ligament (n = 7 and n = 4, respectively), and the gastrophrenic ligament (n = 6 and n = 4, respectively). Sections of fixed tissue were stained with hematoxylin and eosin, Masson's trichrome, and resorcin-fuchsin for analysis of elastic fibers by light microscopy, and elastin area was quantified and expressed as a percentage of the imaged tissue. Results: Elastin and collagen fibers were prominent in all ligaments in patients with GERD alone. In patients with GERD/HH, there was fragmentation and distortion of elastin in the phrenoesophageal ligament and gastrohepatic ligament, and to a lesser degree, in the gastrophrenic ligament. Compared with patients with GERD alone, the presence of hiatal hernia was associated with a reduction in elastin area by more than 50% in the phrenoesophageal ligament ([mean ± SEM] 31.0% ± 3.3% versus 15.1% ± 1.3%, p < 0.01) and gastrohepatic ligament (26.9% ± 0.5% versus 12.5% ± 0.1%, p < 0.008). There was no decrease with respect to elastin in the gastrophrenic ligament. Conclusions: The periesophageal ligaments in patients with GERD are characterized by prominent elastic fibers. In contrast, GERD/HH is associated with depletion of elastic fibers in two of three ligaments supporting the gastroesophageal junction. Elastic fiber depletion in the periesophageal ligaments thereby provides a structural basis for the development of HH. It remains unclear if this represents a primary (etiologic) alteration or if it is a secondary phenomenon.