Angiostrongyliasis is a globally distributed parasitic disease. Early and accurate identification of patients with severe infection is required. In this retrospective study, 81 patients with angiostrongyliasis were divided into two groups: 24 patients with severe disease and 57 with mild disease. Logistic regression analysis was used to determine the factors associated with severe disease. Receiver operating characteristic (ROC) analysis, κ tests, and χ(2) tests were performed. The factors analyzed included: headache (P = 0.013), abnormal cerebrospinal fluid pressure (P = 0.013), and abnormal peripheral blood eosinophil count (P = 0.007). The area under the ROC curve for the activation criteria for angiostrongyliasis (ACA) was 0.914, with a score of ≥ 7 points predicting a severe state; the κ value was 0.744. The incidence of severe angiostrongyliasis increased with increasing score. ACA is a useful tool with high accuracy and reliability for predicting the severity of angiostrongyliasis.