Anti-Ma2-associated encephalitis is a paraneoplastic disorder that predominantly affects the limbic system, diencephalon and brainstem, and is usually associated with tumors of the testis. We report a 35-year-old man with a right testicular mass who presented with multiple neurological complains, and clinical, serological and radiological features compatible with anti-Ma2-associated encephalitis. After three courses of carboplatin, etoposide and bleomycin for metastatic testicular germ-cell tumor, all elevated tumor markers normalized and the retroperitoneal metastases disappeared, but the neurological disorder deteriorated. To our knowledge, this is the first case in which orchiectomy followed by carboplatin, etoposide and bleomycin for a testicular tumor with anti-Ma2 encephalitis was performed.