Mucosa-associated lymphoid tissue (MALT) lymphoma of the gallbladder is rare with six cases reported in the English published reports. Most patients present with symptoms consistent with cholecystitis. We describe a case of extranodal marginal zone B-cell lymphoma of MALT of the gallbladder in a 60-year-old woman who presented with abnormal liver function tests and subsequent finding of gallbladder thickening on ultrasonography. Cholecystectomy revealed a chronically inflamed gallbladder with multiple gallstones. Histology revealed abnormal sheets of small B lymphoid cells which were CD 20 positive, consistent with a diagnosis of MALT lymphoma. The pathogenesis of MALT lymphoma in the gallbladder remains controversial. As the gallbladder does not normally contain lymphocytes, persistent lymphoid proliferation due to chronic Gram-negative infection may represent a critical step in the development and progression of MALT lymphoma. Cholecystectomy without adjuvant chemotherapy is the appropriate first line treatment if there is no other symptomatic disease.