Background: The application of electrodiagnosis is helpful to determine any kind of critical illness neuromyopathy (CINM). However, in Vietnam, neuromuscular electrophysiological studies on ICU patients are not commonly available in medical media. Objective: This study will attempt to give a description of the neuromuscular electrophysiological changes and specify the related factors of CINM in patients having been treated in the ICU within 10 days or more. Materials and methods: The cross-section descriptive study with analysis was conducted on 133 cases from October 2010 through July 2012 at the ICU deparlment of the Tien Giang Hospital. Results: Patients while hospitalized within 10-15 days at the ICU experienced a significant decrease in compound muscle action potentials (CMAP) and sensory nerve action potentials (SNAP). The ratio of motor sensory axonal neuropathy acquired in these patients were 49.62 percent, 20 percent of the cases were combined with demyelinating neuropathy. Nearly twothird of the patients showed signs of newly acquired neuromyopathy from electrodiagnosis (63.16 percent). The related independent factors with CINM included systemic inflammatory response syndrome (OR=3.75), shock condition (OR =2.85), electrolyte disturbances (OR = 2.48), having been hospitalized more than 20 days (OR = 2.95) and mortality in hospital (OR = 3.14). Conclusions: Nerve conduction studies and electromyography are useful for diagnosis of newly acquired neuromuscular diseases in ICU patients. the author should attend related factors with CINM.