Multiple primary malignant neoplasms (MPMN) are tumors that arise independently in the same organ or tissues and different organs; they may present simultaneously (synchronous) or at least 6 months later (metachronous). The authors report the case observed: 20 multiple neoplasms in 5 years (5.8% of the tumors). In the light of the international literature they analyze some aspects of the problem, particularly with regard to the classification, etiopathogenesis, neoplasm associations and possible genetic character for some of there.