From January 1 1994 to March 1 1995 we observed 6 patients with gastric low-grade B-cell lymphoma of MALT type in association with Helicobacter pylori infection. Endoscopically only 3 of the 6 patients presented with pathological findings. All but one patient with metastatic carcinoma received antibiotic therapy for Helicobacter pylori. Follow-up was not possible in one patient who died unexpectedly. In all 4 patients followed-up, eradication of Helicobacter pylori resulted in regression of the malignant lymphoma. During the median follow-up time of 7 months (2-13 months) no relapse of lymphoma was observed. Our results confirm that gastric low-grade B-cell lymphoma of MALT type can regress after eradication of Helicobacter pylori.