Neuromuscular complications of cancer are common and can affect any component of the peripheral nervous system from peripheral nerve cell body to muscle. Perhaps the most common complication is a length-dependent symmetric axonal polyneuropathy that is often multifactorial in etiology, resulting from metabolic and treatment effects of the primary malignancy. However, neuromuscular disorders may also be the presenting complaint in many conditions, including disorders caused by malignant infiltration of nerve and disorders cause by paraneoplastic syndromes. Although many of the paraneoplastic conditions are poorly responsive to treatment, not all are, and one hopes that prompt diagnosis of the underlying malignancy will lead to improved patient outcome. Recognition of iatrogenic neuromuscular complications is also important to modify treatment protocols when possible and thus decrease the risk of long-term neurologic disability.