The development of eosinophilic gastritis immediately after Helicobacter pylori eradication has not previously been described: A 62-year-old woman developed eosinophilic gastritis immediately after a triple therapy for Helicobacter pylori eradication, consisting of pantoprazole, amoxicillin and clarithromycin. She suffered from burning epigastric pain and loss of appetite. Blood eosinophilia, gastritis and eosinophilic infiltration of the gastric corpus wall were detected. The treatment with low-dose prednisolone led to remission of the blood eosinophilia, complaints, gastritis and eosinophilic infiltration. The remission persisted after the prednisolone treatment had been finished. Eosinophilic gastritis can be diagnosed only by pathohistological examination. This need for biopsy should be stressed, because the usual gastritis treatment with proton pump inhibitors fails in cases of eosinophilic gastritis. Helicobacter pylori does not seem to play a significant role in the aetiopathology of this disorder. In our case, we suggest that the eradication drug therapy actually caused the disease.