Introduction: Neonatal septicaemia is one of the major factors contributing to the high perinatal and neonatal mortality and morbidity. The definite diagnosis of septicemia is made by a positive blood culture which requires a minimum period of 48-72 hours and yields a positive result in 30-70% of cases. Hence there is a critical need for laboratory tests that aid in the rapid diagnosis of neonatal sepsis. Objective: To evaluate the neonatal hematological parameters of clinically diagnosed cases of sepsis, as ones which can be used to formulate a scoring system in early diagnosis of neonatal sepsis. Design: A diagnostic study conducted at the Neonatal Intensive Care Unit of a tertiary care teaching hospital. Methods: This study consists of 100 neonates admitted at Neonatal Intensive Care Unit at the Dr. D.Y. Patil Medical Hospital, Pimpri, Pune, who were clinically suspected of sepsis. The neonatal hematological parameters included were total leukocyte count, total neutrophil count, lymphocytes, immature cells, immature to total leukocyte ratio, immature to mature cells ratio, nucleated red blood cells, platelet count, and degenerative cells (toxic granules & dhole bodies). These parameters were evaluated based on the standard reference values given by Rodwell et al and were graded as a) score >5- sepsis, score of 3 to 4 – probable sepsis and c) score of <3 as no sepsis. A blood culture was the standard indicator for proven sepsis. Results: There were 21 out of 100 neonates (21%) who had culture proven sepsis and they were predominantly males and less than one day old. Among the different parameters, the sensitivity of TLC was 100%, increased PMN count showed a sensitivity of 95%. The overall sensitivity of culture positive neonates with a score of more than 5 was 69%, specificity was 76% and disease prevalence was 29%. Conclusion: The sensitivities of the various screening parameters were found to be satisfactory in identifying early onset neonatal sepsis. Hematological scoring system is a simple and feasible diagnostic tool to guide towards the decision-making for a rationale treatment.