Background. Lymphocytic gastritis is a rare condition found in approximately 1% of dyspeptic patients. An association with Helicobacter pylori infection has been described. Hypertrophic lymphocytic gastritis is a rare cause of gastrointestinal protein loss. Here, we describe a patient with hypertrophic lymphocytic gastritis, in whom gastrointestinal protein loss resolved completely following H. pylori eradication. Case Report. A 38-year old obese man without gastrointestinal symptoms showed a markedly decreased serum protein (53 g/l, normal 66-85 g/l), a decreased serum albumin (33 g/l, normal 35-52 g/l) and decreased serum immunoglobulin G and immunoglobulin M levels. A renal cause for protein loss was excluded, liver function was normal. Endoscopy of the upper gastrointestinal tract revealed enlarged rigid gastric folds, and an H. pylori-associated lymphocytic gastritis. 99mTc-labelled albumin scintigraphy showed an increased activity in the upper left abdomen compatible with protein secretion in the stomach, and tracer pooling in the upper small bowel. Push enteroscopy with histology demonstrated a normal upper small bowel. Two months after eradication therapy, cure of H. pylori infection was documented and serum protein (71 g/l) and albumin (41 g/l) had returned to normal, while lymphocytic gastritis was still present. One year after eradication therapy endoscopy of the upper gastrointestinal tract and histology and laboratory values were normal. Conclusion. Protein-losing gastropathy caused by H. pylori-associated hypertrophic lymphocytic gastritis can be cured solely by H. pylori eradication therapy.