The use of neuromuscular blockers (NMB) is a frequent practice in Intensive Care Units. However most of the experience with the use of these agents come from the operating room used to deal with patients with different characteristics from those admitted in the ICU. Recent advances on neuromonitoring and the commercialization of newer agents make necessary the update in the management of NMB in the ICU. The NMB agent should be chosen attending to its pharmacokinetics and the physiopathology of the critically ill patient. Those NMB with organ-independent metabolism as well as those with rapid onset of action are the preferred ones for the use in the critically ill patient substituting older depolarizing agents and those whose metabolism is dependent on the liver and/or kidney, organs frequently impaired in the critically ill patients. Neuromuscular blocking in the critically ill patient should be done according to protocols and monitor its effects in order to avoid complications related to its prolonged use.