The aim of this study was to summarize the findings of previous studies focusing on whether the risks of certain neurotoxicities are correlated to the programmed death 1 (PD-1) inhibitor nivolumab versus other chemotherapy or immunotherapy drugs. Six eligible studies, including 3,023 patients, were considered in the meta-analysis. The risk ratios (RRs) of fatigue, headache, dysgeusia, vertigo, paresthesia, anxiety or malaise and peripheral neuropathy were 0.908 (95% confidence interval [95% CI]: 0.724, 1.138; P=0.402), 0.841 (95% CI: 0.606, 1.168; P=0.302), 0.423 (95% CI: 0.132, 1.357; P=0.148), 0.762 (95% CI: 0.475, 1.223; P=0.261), 0.411 (95% CI: 0.232, 0.730; P=0.002), 1.049 (95% CI: 0.094, 11.752; P=0.969) and 0.192 (95% CI: 0.039, 0.935; P=0.041), respectively. Our analysis supported that the PD-1 inhibitor nivolumab did not cause increased or decreased risks of fatigue, headache, dysgeusia, vertigo and anxiety or malaise and was associated with decreased risks of paresthesia and peripheral neuropathy as compared with controls. These outcomes indicated that although clinicians should be attentive of the side effects of nivolumab, in terms of nervous system side effects, nivolumab is generally safe
