Summary: Myasthenia gravis is the best studied example of a neuromuscular junction disease. The most important form is the autoimmune form of the disease, which is caused by the binding of autoantibodies to proteins involved in neuromuscular transmission -the nicotinic ACh receptor or (less commonly) the muscle-specific tyrosine kinase. These interactions reduce the number of functional receptors and alter the neuromuscular junction morphology. Prevalence rates have increased to 200-400 cases per million in the last decades. Acquired myasthenia gravis is characterized by skeletal muscle weakness that worsens with exertion, and improves with rest. The involvement of extrinsic ocular muscle presents as the initial symptom in about two-thirds of patients, usually progressing and affecting other bulbar muscles and limb muscles, which is called generalized myasthenia gravis. During the past decades, remarkable progress has been made in understanding of myasthenia gravis, and as nowadays this disease is highly treatable. Early recognition and diagnosis is crucial.