The term extranodal lymphoma refers to lymphoma arising in tissues other than lymph nodes or major lymphoid organs (1). The GI tract is commonly involved by lymphoma. Although lymphomas of the liver and the biliary tree are uncommon, they are well described in the literature. However, there are only nine cases of primary lymphoma of the gallbladder reported in the English literature. We report a patient with primary gallbladder lymphoma diagnosed preoperatively by ultrasound, with disease confined to the gallbladder on pathology specimens and radiological examination. His rapid disease progression to diffuse abdominal involvement in 6 wk points to the importance of a timely diagnosis. We postulate that delays in making the diagnosis may lead to the underdiagnosis of primary lymphoma of the gallbladder.