A spayed female, 5-year-old, weighing 2.7 kg, domestic short hair cat was referred to Veterinary Medical Teaching Hospital, Seoul National University. The clinical signs of this patient were weight loss, sneezing, respiratory distress, nasal discharge, epistaxis, ocular discharge, left exophthalmos, and left facial edema and deformity. The laboratory tests represented mild leukocytosis. On the skull radiographs, soft tissue density filled nasal cavity with loss of turbinate detail was found. Destructive and lytic changes of the left nasal bone with soft tissue swelling were identified. On the thorax radiographs, there were a tracheobronchial lymph node swelling and a soft tissue round mass in the left caudal lung field. On computed tomographic scan images, asymmetrical destruction of turbinate and nasal septum and increased soft tissue opacity in the nasal cavity were identified. Destruction of the lateral maxillary bone, invasion to the left retrobulbar region, and craniodorsal deviation of the left eye were seen. Also, there was lysis of hard palate and cribriform plate. Invasion to the brain was found. The patient was diagnosed as nasal lymphoma by cytology and histopathology.