A 7-year-old, male castrated, domestic shorthair cat was presented to the Cornell University Hospital for Animals Emergency Service for a 5 week history of lameness after falling from an indoor balcony. The day after this incident occurred, the patient was taken to its primary care veterinarian where pelvic limb radiographs were performed with no significant findings reported. In the subsequent days, the patient began to exhibit a right pelvic limb lameness which progressed into knuckling at the paw. At this time, referral to Cornell was elected. On presentation, he was ambulatory on 3 limbs with severe muscle atrophy evident in the right pelvic limb. Neurologic exam revealed a non weight bearing right pelvic limb monoparesis, low tail carriage, a weak perinea I reflex, and an absent withdrawal reflex and proprioception. The patient was booked into the hospital for overnight supportive care and transfer to the Neurology service. Imaging revealed a severe right sided radiculopathy involving spinal nerves L6, L7, S1. A diffuse, right sided gluteal myopathy was also detected. Euthanasia was elected while still under general anesthesia. A teaching necropsy was performed and a final diagnosis of right sided sciatic lymphomatosis, or peripheral nerve lymphoma, was achieved.