Prognostication in patients with acute neuromuscular disorders presenting to the intensive care unit (ICU) can be challenging, even for experienced providers. The various neuromuscular conditions that result in severe limb and respiratory weakness are heterogeneous with regard to their pathophysiology, natural history, and response to therapy. Furthermore, many patients with respiratory weakness require ventilatory support and can have relatively protracted ICU and hospital stays where systemic complications, such as delirium, hospital-acquired infections (particularly in immunosuppressed patients), deep venous thromboses and thromboembolism, sedation requirements, pre-existing diagnoses, affective disorders, and immobilization may all confound the ability to predict long-term recovery. Yet, outcome data on some of the most common etiologies of neuromuscular weakness in the ICU, including myasthenia gravis (MG), Guillain–Barré syndrome (GBS), ICU-acquired weakness (ICUAW), and amyotrophic lateral sclerosis (ALS) is available and can aid tremendously in guiding prognostication when taken in the context of the individual patient’s unique clinical condition.