It is challenging to differentiate between central nervous system (CNS) virus infections and neurological autoimmune diseases in the emergency department. Considering their different pathogenesis, we assume they differ in neuropsychiatric symptoms and laboratory results. A total of 80 patients were included in this study, 50 with CNS virus infections and 30 with CNS autoimmune diseases, confirmed by a polymerase chain reaction (PCR) of cerebrospinal fluid (CSF). A binary logistic regression model and receiver operating characteristic (ROC) curve were employed to examine the discrimination between the two types of diseases based on neuropsychiatric symptoms and laboratory results. Compared to patients with neurological autoimmune diseases, patients with CNS virus infections had a higher incidence of abnormal behavior (p = 0.026) and abnormal sensation/thought (p = 0.029); higher total (p = 0.005), direct (p = 0.004), and indirect bilirubin (p = 0.004); and increased CSF cell (p = 0.01) and CSF white cell counts (p = 0.01). Patients with disturbance of consciousness and abnormal sensation/thought were 7.79-fold and 5.07-fold more likely to be diagnosed with CNS virus infections (OR = 7.79, p = 0.008; OR = 5.07, p = 0.032). Each unit increase in blood indirect bilirubin concentration and CSF white cell counts increased the risk of developing CNS virus infections by 1.25-fold and 1.01-fold (OR = 1.25, p = 0.016; OR = 1.01, p = 0.011). ROC analysis showed that the area under the curve was 88.0% (p < 0.001). Our study found that patients with CNS viral infections tend to have higher blood indirect bilirubin concentration, CSF leukocyte count, frequency of disorders of consciousness, and abnormal sensation and thought, which may help differentiate them from those with neurological autoimmune diseases.