As with most illnesses, the prognosis is best when identified early and treated aggressively. In these cases NMS is usually not fatal, although there is currently no agreement on the exact mortality rate for the disorder.
Studies have given the disorder a mortality rate as low as 5% and as high as 76%, although most studies agree that the correct percentage is in the lower spectrum, perhaps between 10% – 15%. Re-introduction to the drug that originally caused NMS to develop may also trigger a recurrence, although in most cases it does not.