Critical illness neuromyopathy (CINM) is suggested by bilateral diffuse weakness predominant in the proximal part of the limbs after improvement of the acute phase of critical illness. Although muscle and peripheral nerve are often involved in combination, muscle involvement alone is increasingly identified on electrophysiologic investigation, including direct muscle stimulation. CINM frequently involves the respiratory muscles and may result in delayed weaning and prolonged mechanical ventilation. Besides muscle immobilization and prolonged sepsis-induced multiorgan failure, which are risk factors for CINM, hyperglycemia and use of corticosteroids might have a deleterious effect on the neuromuscular system in critically ill patients, suggesting opportunities for preventive interventions.