Ammar H et al. - A 64-year-old female patient presented with acute cerebellar ataxia. After ruling out vascular, infectious, metastatic, demyelinating, and medication etiologies, a paraneoplastic origin for her illness was determined. A renal mass was discovered and found to be renal cell carcinoma. Her symptoms resolved after a radical nephrectomy. Physicians should consider the diagnosis of paraneoplastic neurologic syndromes whenever a thorough evaluation fails to explain neurologic abnormalities.