Introduction: Electrolyte abnormalities are frequently encountered in sick neonates. They occur in a variety of conditions including neonatal sepsis and may remain unrecognized leading to morbidity and mortality irrespective of the primary disease. So, timely recognition, a high index of suspicion and a thorough understanding of common electrolyte abnormalities are necessary to ensure their correction. Objective: To assess the Outcome of Neonates with Septicaemia with Different Types of Electrolyte Abnormality. Methods: All neonates who were suffering from septicaemia and admitted in BSMMU from 1st January 2011 to 15th September 2011 and fulfilled the inclusion criteria were evaluated. Results: During the study period total 120 neonates were admitted with the diagnosis of septicaemia in the Department of Neonatology, BSMMU, and Dhaka, Bangladesh. Among the neonates mean age were 9.26±4.58 days, mean weight 2282.68±580.40 gm, mean gestational age was 35.68±2.40 weeks. Among the neonates with septicaemia males were 66 (55%) and females were 54 (45%) and male to female ratio was 1.2:1. Among 120 cases of septicaemia 57 (47.5%) were early onset and 63 (52.5%) were diagnosed as late onset neonatal sepsis. Among the 120 neonates with septicaemia 37 (30.83%) died and 83 (69.17%) survived. Neonates with dyselectrolytemia were found significantly associated with prolonged hospital stay in comparison to those with normal electrolytes level (p<0.05). Hyponatremia, Hypokalemia, Hypernatremia and mixed electrolyte abnormalities were significantly associated with prolonged hospital stay (P< 0.05) but hyperkalemia was not found significantly associated with prolonged hospital stay (p>0.05). Hyponatremia, hypokalemia and mixed electrolyte abnormalities were significantly associated with higher mortality (P<0.05). Hypernatremia and Hyperkalemia were not found significantly associated with higher mortality (P>0.05). Conclusion: Electrolyte abnormalities are common in neonates with septicaemia. We found electrolyte abnormalities in 35% cases. Hyponatremia (20%) was the commonest abnormality followed by hyperkalemia (15.8%). Hyponatremia, hypokalemia and mixed electrolyte abnormalities were found to be significantly associated with higher mortality in this study.