The electrodiagnostic (EDX) examination in patients with suspected Neuromuscular Junction (NMJ) disorder constitutes the most advanced and complex type of EDX studies. Understanding the anatomy and physiology of neuromuscular transmission is prerequisite for the comprehension and planning of EDX studies in patients with suspected NMJ disorders. In addition to routine nerve conduction studies and conventional needle electromyography (EMG), the EDX studies, which are most useful in the diagnosis of NMJ disorders, include repetitive nerve stimulation and single fiber EMG.