Myasthenia gravis is a neuromuscular disease of insidious onset, characterized by weakness and fatigability of voluntary muscles. Most patients present with symptoms relating to the head and neck and thus may be seen first by the otolaryngologist. Predominant symptoms may be ocular (ptosis or diplopia) or related to fatigue of the oropharyngeal or laryngeal musculature (dysarthria, dysphonia, or dysphagia). Alleviation of muscular weakness and fatigability after administration of anticholinesterase drugs is pathognomonic of myasthenia gravis.