A six year old female spayed ferret was presented to the Exotics Service at Cornell University Hospital for Animals for evaluation of acute hind limb weakness. Physical exam findings on the ferret included paraparesis, splenomegaly, a left cranial abdominal mass and tail hypotrichosis. Differential diagnoses for the splenomegaly included extramedullary hematopoiesis, lymphoma, cardiac disease and hypersplenism. Complete blood count results revealed no abnormalities; chemistry panel results showed nonspecific changes including hyperproteinemia, hypercalcemia and hyperphosphatemia. Cytologic evaluation of ultrasound-guided fine needle aspirates of the spleen confirmed a diagnosis of lymphoma. This case report will discuss lymphoma in the ferret with regards to diagnostics, classification of disease and treatment modalities, in addition to describing differences from lymphoma in traditional companion animals.