Tehran University of Medical Sciences Current Journal of Neurology 2717-011X 18 3 2019 06 13 119 126 EN Davood Fathi Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Brain and spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Shahriar Nafissi Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Shahram Attarian Reference Centre for Neuromuscular Disorders and ALS, CHU La Timone, Aix-Marseille University, Marseille, France Christoph Neuwirth Neuromuscular Disease Unit/ALS Clinic, Kantonspital St. Gallen, St. Gallen, Switzerland Farzad Fatehi Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Iranian Center of Neurological Research, Tehran University of Medical Sciences, Tehran, Iran 2017 12 09 2019 06 13 Motor unit number index (MUNIX) is an electrophysiological technique to give an estimate of functioning motor neurons in a muscle. For any given neurophysiological technique for the use in clinical or research studies, reproducibility between different operators and in a single operator in different times is one of the most important qualities, which must be evaluated and approved by different examiners and centers. After its introduction, testing the reproducibility of MUNIX was the aim of many studies to show this quality of the technique. In this review, we aimed to summarize all the studies, which have been performed up to now to approve MUNIX reproducibility in amyotrophic lateral sclerosis comparing healthy individuals. https://ijnl.tums.ac.ir/index.php/ijnl/article/view/1463