The causes of central nervous system infection from the first 1,065 lumbar punctures at Mahosot Hospital, 2003-2011, have been analysed. The mortality was high at 26.3%. Patients with bacterial infection were more likely to have a history of diabetes than those without. Factors that showed strong association with death were higher CSF lactate and lower GCS. The Lao data suggest that particular attention should be paid to patients presenting with decreased GCS and the provision of supportive care for unconscious patients, such as high-dependency units (HDU), along with appropriate urgent antimicrobial therapy may be key factors in improving outcome.