Myasthenia gravis (MG) is a neuromuscular autoimmune disease that occurs with antibody development against nicotinic acetylcholine receptors. The 19-year-old female patient was admitted to the emergency service with the complaint of difficulty in swallowing for 1 week. There was no history of abnormality in the patient. The uvula sola was deviated in the physical examination of the patient. The obtained brain, cervical and thorax CT and the diffusion MRI of the patient were normal. Consultation was requested for the patient from neurology, and the patient was hospitalized at the neurology clinic with the pre-diagnosis of myasthenia gravis. The case that acutely occurs in myasthenic patients and is characterized by severe loss of strength and respiratory deficiency is known as myasthenic crisis (MC). The diagnosis of MC must be confirmed by considering the patient’s history and signs of physical and neurological signs. Myasthenia gravis is an autoimmune disease that is concerned with the neuromuscular junction, and it may lack a diagnosis in the initial periods. We should include myasthenia gravis as a pre-diagnosis in patients with difficulty in swallowing that are admitted to emergency services as a result of upper respiratory infections such as acute pharyngitis and acute tonsillitis.