Using the usual diagnostic tools like barium swallow examination, endoscopy, and manometry, we are able to diagnose a hiatal hernia, but it is not possible to predict the size of the hernia opening or, respectively, the size of the hiatal defect. At least a correlation can be expected if the gastroesophageal junction is endoscopically assessed in a retroflexed position, and graded according to Hill. So far, it is not possible to come to a clear conclusion how the hiatal closure during hiatal hernia repair should be performed. There is no consensus on using a mesh, and when using a mesh which type or shape should be used. Further studies including long-term results on this issue are necessary. However, it seems obvious to make the decision depending on certain conditions found during operation, and not on preoperative findings.