AbstractA 61‐year‐old man was found to have small‐cell lung cancer following a 1‐year history of a progressive peripheral sensorimotor neuropathy. The neuropathy initially improved following chemotherapy, but subsequently progressed to the point of respiratory failure. Treatment with plasma exchange, additional chemotherapy, and radiotherapy resulted in a sustained complete tumor remission and neurologic recovery. The role of plasma exchange is unclear, but its use should be considered in cases of severe sensorimotor neuropathy unresponsive to antineoplastic tr