Angiostrongylus cantonensis is mainly caused eosinophilic meningitis in humans, whereas a minority of patients develop encephalitic angiostrongyliasis (EA). EA is an extremely fatal condition, and the clinical factors predictive of EA have never been reported. A comparison study was conducted in a hospital situated in an endemic area of Thailand. We enrolled 14 and 80 angiostrongyliasis patients who developed encephalitis and meningitis, respectively. Logistic regression analysis was used to assess the clinical variables predictive of encephalitis. Age (adjusted odds ratio [OR], 1.22; 95% confidence interval [CI], 1.05-1.42), duration of headache (adjusted OR, 1.26; 95% CI, 1.03-1.55), and fever > 38.0 degrees C (adjusted OR, 37.05; 95% CI, 1.59-862.35) were identified as statistically significant factors for EA prediction. Elderly patients with angiostrongyliasis experiencing fever and prolonged headaches were at the highest risk of developing EA.