Although infiltration of the gallbladder by lymphoma is rare, it has to be considered in the differential diagnosis of patients presenting with cholecystitis-like symptoms. The most common lymphomas masquerading as acute cholecystitis are mucosa-associated lymphoid tissue lymphoma and large B-cell lymphoma. We describe a 75-year-old patient who presented with an acute cholecystitis-like picture, featuring chronic lymphocytic leukemia (CLL) with gallbladder wall involvement as the initial disease presentation. The cholecystectomy specimen showed perineural invasion present within the gallbladder wall, which likely accounted for the patient's right upper quadrant abdominal tenderness. In this way, we would like to alert clinicians and pathologists alike to CLL as yet another cause of a cholecystitis-like symptomatology.