The diagnosis of myasthenia gravis in the patient who demonstrates the classical signs and symptoms is comparatively simple. However, the very early case or one in which there are equivocal symptoms still defies the diagnostic acumen of the physician. This paper presents a review of the diagnostic methods in myasthenia gravis, with the description of a new clinical therapeutic test. Since 1935, when Walker1first demonstrated the remarkable effects of neostigmine and Viets and Schwab2described its diagnostic use, the diagnosis of myasthenia gravis has been made with ever increasing frequency. Various mechanical and electrical investigative tests have also been used in the diagnosis of myasthenia gravis. To have a high degree of suspicion of the disease is always a most important factor in its diagnosis. When a history is taken, the proper questions can then be asked, with special reference to the onset of weakness, its relationship