Mucosa-associated lymphoid tissue (MALT) type lymphoma has generally been thought not to show increased fluorine 18-fluorodeoxyglucose (FDG) accumulation on positron emission tomography (PET), based on previous research. Only a limited numbers of articles have been published on this topic, however, involving a small number of cases. Although positive FDG PET results might be uncommon in this entity, a case of increased FDG accumulation in a case of MALT type lymphoma of the lung is presented.