Objective − To evaluate prognostic indicators of mortality in children admitted to the Paediatric Intensive Care Unit (PICU) and to correlate blood lactate levels with Pediatric Risk of Mortality (PRISM) III scores.Methods − A cross sectional study was conducted between March 2021 and October 2022 in the PICU of the P S Govindasamy (PSG) Institute of Medical Sciences and Research. On the basis of the laboratory and clinical parameters, the PRISM III score was calculated at admission. Lactate levels were measured at admission and 24 hours after admission.Results − The study included 107 patients of whom the majority (54.2%) were female. The median patient age was 3 years and the median duration of PICU stay was 4 days. Among the hospitalized patients, 90.7% were survivors, with female patients having an 8.8-fold higher risk of mortality compared to males (P=0.05). The serum lactate value in survivors (2.95 mmol/L) was much lower in comparison to non-survivors (3.11 mmol/L). The PRISM III value measured at the time of admission in survivors (8) was low when compared to non-survivors (16.50). The area under the curve (AUC) for PRISM III was 0.884 compared to lactate levels (0.831).Conclusion − A significant positive correlation was seen between the PRISM III score and lactate levels. The study indicates that monitoring patients admitted to the PICU in relation to their PRISM III score and lactate levels can improve their overall prognosis and facilitate early resuscitation.