Background.-Jolt accentuation has been considered to be the most sensitive physical finding to predict meningitis. However, there are only a few studies assessing the diagnostic accuracy of jolt accentuation. Therefore, we aimed to evaluate the diagnostic accuracy of jolt accentuation and investigate whether it can be extended to patients with mild altered mental status. Methods.-We performed a single center, retrospective observational study on patients who presented to the emergency department in a Japanese tertiary care center from January 1, 2010 to March 31, 2016. Jolt accentuation evaluated in patients with fever, headache, and mild altered mental status with Glasgow Coma Scale no lower than E2 or M4 was defined as "jolt accentuation in the broad sense." Jolt accentuation evaluated in patients with fever, headache, and no altered mental status was defined as "jolt accentuation in the narrow sense." We evaluated the sensitivity and specificity in both groups. Results.-Among 118 patients, the sensitivity and specificity of jolt accentuation in the broad sense were 70.7% (95% confidence interval (CI): 58.0%-80.8%) and 36.7% (95% CI: 25.6%-49.3%). The positive likelihood ratio and negative likelihood ratio were 1.12 (95% CI: 0.87-1.44) and 0.80 (95% CI: 0.48-1.34), respectively. Among 108 patients, the sensitivity and specificity of jot accentuation in the narrow sense were 75.0% (95% CI: 61.8%-84.8%) and 35.1% (95% CI: 24.0%-48.0%). The positive likelihood ratio and negative likelihood ratio were 1.16 (95% CI: 0.90-1.48) and 0.71 (95% CI: 0.40-1.28), respectively. Conclusions.-Jolt accentuation itself has a limited value in the diagnosis of meningitis regardless of altered mental status. Therefore, meningitis should not be ruled out by negative jolt accentuation.