The role of monoclonal antibody (mAb) therapies in treating medical conditions has expanded tremendously since its inception in the 1970s, and their use in neurologic conditions has increased in just the past few years. Currently, mAb treatments are being tested in conditions ranging from neuromuscular disorders to demyelinating diseases. What is now considered experimental therapy may soon become common. In addition, neurologic adverse effects have been reported during the use of mAb therapy in nonneurologic conditions that neurologists should be able to recognize. Because of the rapid increase in the use of mAb treatments, this review highlights their use in neurologic conditions and their neurologic adverse effects.