We validated a handheld point-of-care lactate (POCL) monitor's ability to measure lactate in cerebrospinal fluid (CSF) and diagnose bacterial meningitis in Uganda. There was a strong linear correspondence between POCL and standard laboratory lactate test results (R(2) = 0.86; P < 0.001). For 145 patients with clinical meningitis, the area under the receiver operating characteristic curve for the prediction of bacterial meningitis by CSF POCL was 0.92 (95% confidence interval = 0.85-0.99, P < 0.001). A CSF POCL concentration of 7.7 mmol/L provided 88% sensitivity and 90% specificity for the diagnosis of bacterial meningitis. CSF POCL testing had excellent use in the diagnosis of bacterial meningitis, and it may be useful where CSF analyses are delayed or laboratory infrastructure is limited.