The clinical data, diagnosis, treatment, and prognosis of 10 patients with anti-glutamic acid decarboxylase (GAD) antibody-related cerebellar ataxia in Department of Neurology, Peking Union Medical College Hospital, from May 2015 to November 2021 were retrospectively analyzed. There were 8 female patients with a median age of 55 years old. Patients mainly presented with gait ataxia (10/10), dizziness (8/10), diplopia (6/10), and dysarthria (5/10). Four of them were complicated with other autoimmune disease, including vitiligo (3/4), Hashimoto thyroiditis (1/4), thrombocytopenia (1/4), and small cell lung cancer (1/4). All patients received immunotherapy, 6 out of 10 exhibited a good response, and half of them had satisfied functional prognosis. Patients of anti-GAD antibody-related cerebellar ataxia may be complicated with other autoimmune diseases, but underlying tumor is rare. More than half of patients have a good response to immunotherapy and satisfied prognosis.