A 4‐month‐old male domestic shorthair cat with a 36‐h history of acute and progressive painful paraplegia was referred. The neurological examination was consistent with T3‒L3 myelopathy. Magnetic resonance imaging of the thoracolumbar region revealed an extradural mass at the level of T12‒T13 that caused moderate spinal cord compression. The cat underwent T12‒T13 dorsal laminectomy decompressive surgery, and its neurological signs improved shortly after surgery. A diagnosis of epidural spinal steatitis was reached based on histopathological examination of the compressive mass. To the authors’ best knowledge, this is the first description of the magnetic resonance imaging and computed tomographic findings of histopathologically confirmed idiopathic sterile pyogranulomatous inflammation of epidural fat in a cat. Epidural idiopathic sterile pyogranulomatous steatitis should be included as a possible differential diagnosis in young cats with acute and progressive T3‒L3 myelopathy signs.