Untreated gastric MALT lymphoma can present with clinical symptoms such as abdominal pain and bloating, and can be life-threatening as the disease progresses. Gastric MALT lymphoma, i.e. gastric mucosa-associated lymphoid tissue lymphoma, is a non-Hodgkin’s lymphoma with marginal zone lymphoma from extranodal mucosa-associated lymphoid tissue. If left untreated, symptoms of gastrointestinal involvement such as abdominal pain, bloating, black stools, acid reflux, nausea and weight loss can occur with the progression of the disease. If the disease progresses further, it can be life-threatening. The prognosis of gastric mucosa-associated lymphoid tissue lymphoma can be improved with effective treatments such as chemotherapy, radiotherapy and immunotherapy. However, the specific efficacy varies from person to person. It is recommended to seek medical treatment in time for diagnosis and treatment.