Tolosa-Hunt syndrome is an uncommon disease that exhibits unilateral periorbital pain or headache, accompanied by cranial nerve palsies. Myasthenia gravis is an acquired immune system disease involving the neuromuscular junction. One rare case of Tolosa-Hunt syndrome combined with ocular myasthenia gravis had been reported in the literature, but not general myasthenia gravis. We present a patient with a probable coincidence of Tolosa-Hunt syndrome and general myasthenia gravis. A 63-year-old male exhibited episodes of unilateral headache with double vision, bilateral ptosis, vision decrease in the left eye and left facial hypoesthesia, muscle weakness in limbs and neck. The muscle weakness was fluctuating and could be relieved by rest. Blood analysis, cranial magnetic resonance imaging, magnetic resonance angiography/venogram) and orbit/mediastinum computed tomography demonstrated no abnormalities. Serum myasthenia gravis related antibodies detection showed positive titin- antibodies and ryanodine receptor antibodies. Corticosteroid and pyridostigmine bromide treatments were effective. Each of the patient’s symptoms had almost disappeared at the third-month follow-up. We speculate on the etiology of Tolosa-Hunt syndrome with general myasthenia.