BACKGROUND Hyperglycaemia is common in children admitted in the intensive care unit and this has been reported to be associated with increased mortality and morbidity. Aims-To study the correlation between hyperglycaemia and outcome in critically ill children with central nervous system disease admitted in the Paediatric Intensive Care Unit (PICU) of a tertiary hospital in South India. MATERIALS AND METHODS A prospective observational study was conducted from August 2011 to January 2012 in the PICU of Government Medical College, Kozhikode, a major referral hospital in North Kerala. The Institutional Ethics Committee approved the study. Children in the age group of 29 days to 12 years with CNS disease admitted to the PICU were included. Blood glucose was measured with glucometer at admission, at 6 hours and 12 hourly for first 24 hours or till the child attained normoglycaemia. The children were assessed for outcome till discharge from the hospital. Outcome was assessed on the basis of Glasgow Coma Scale (GCS), neurological deficit or death. RESULTS Out of 226 children, 33 children (14.6%) had hyperglycaemia at hospitalisation. Two children died. No significant association was found between blood sugar at admission and GCS or neurological status at discharge.