Neurotoxicity caused by traditional chemotherapy and radiotherapy is widely recognized in patients with cancer. The adverse effects of newer therapeutics, such as biological and immunotherapeutic agents, are less well established, and are associated with considerable neurotoxicity in the central and peripheral nervous systems. This Review addresses the main neurotoxicities of cancer treatment with a focus on the newer therapeutics. Recognition of these patterns of toxicity is important because drug discontinuation or dose adjustment might prevent further neurological injury. Knowledge of these toxicities also helps to differentiate treatment-related symptoms from progression of cancer or its involvement of the nervous system. Familiarity with the neurological syndromes associated with cancer treatments enables clinicians to use the appropriate treatment for the underlying malignancy while minimizing the risk of neurological damage, which might preserve patients' quality of life.