Myasthenia gravis (MG) is regarded as autoimmune disorder of neuromuscular transmission and apparently is due to formation of humoral antibody that cross-link to acetylcholine receptor at skeletal muscle end plate. Patients with autoimmune diseases often have circulating antibodies to a variety of different autoantigens and show a variety of manifestations of autoimmune diseases in more than one organ. Therefore, MG patients frequently have manifestations of autoimmune diseases such as thyroid disease, rheumatoid arthritis and systemic lupus erythematosus. But MG in association with premature ovarian failure (POF) rarely has been described. A case of MG with POF and thyroid autoantibodies was experienced and presented with a brief review of literature.