A case of primary lymphoma of the gallbladder is described which is rare in the medical literature. A 76 year old man presented with acute cholecystitis and septicaemia. Investigation showed a lung abscess and a gallbladder mass. The mass was thought to be an empyema and cholecystostomy was performed. Biopsy of the gallbladder wall showed high-grade B cell lymphoma. The patient unfortunately succumbed to overwhelming septicaemia in the postoperative period. Postmortem examination confirmed primary lymphoma of the gallbladder without dissemination.