We describe a patient with mucosa-associated lymphoid tissue (MALT) type lymphoma of the gallbladder who developed concurrent acute myeloid leukemia (M2). She was admitted because of progressive jaundice and underwent cholecystectomy. Histologic examination of the gallbladder showed diffuse proliferation of atypical lymphoid cells and a formed lymphoepithelial lesion. Because of progressive thrombocytopenia, a bone marrow tap was performed 25 days after the operation. Bone marrow contained 65.5% blasts, and was positive for peroxidase, CD33 and HLA-DR, and negative for lymphoid markers. We discuss the rare association of these disorders.