Gastric MALT lymphoma is the most prevalent low-grade marginal zone lymphoma. It is now well demonstrated that gastric MALT lymphoma is strongly related to Helicobacter pylori infection. Prolonged remission of lymphoma is achieved in more than 50% of patients after Helicobacter pylori eradication. Two factors of tumor response were found: presence of perigastric lymph nodes at endoscopic ultrasonography was related to a failure in 2 out of 3 patients; presence of a translocation t (11; 18) with the fusion of two genes implicated in B lymphocytes apoptosis was related to a failure in most of patients. Further studies are needed to determine the most adapted treatment in non-responding patients. A long-term endoscopic follow-up is recommended due to the increased risk of gastric adenocarcinoma in spite of Helicobacter pylori eradication.