Two adult cases of acute gastric mucosal lesions (AGML) caused by Helicobacter pylori infection were confirmed by spontaneous eradication during the follow-up period. The clinical course of the initial infection by H. pylori in adults with AGML remains unclear, whether it is transient or progresses to a persistent infec-tion. In these two reported cases, gastric biopsies at the time of the onset revealed the presence of H. pylori; however, serum H. pylori antibodies performed at the same time were negative. Retesting for H. pylori serum antibody, after six months in one and after two months in the other, was negative, confirming spontaneous eradication.