Introduction: Encephalitis is a severe central nervous system infection of the brain parenchyma leading to neurologic dysfunction, such as headaches and altered levels of consciousness. Acute encephalitis is one of the important causes of PICU admission. In most cases causes are unidentified, but causes are thought to be viral in many cases. Objective: To assess the clinical aspects and outcome in children admitted to PICU with acute encephalitis. Methods: This is a retrospective study conducted in the PICU of Dhaka Shishu (Children) Hospital in cases admitted over a period of one year, from January 2019-December 2019. Age group included was from 2 month to 12 years. All cases admitted with symptoms suggestive of acute encephalitis were included. History and relevant factors were collected from history sheet including clinical examination findings and were analyzed. Results: More cases are found in 1-5 years age group with mean age being 3.5±3.3 years. Similarity was seen regarding death in case of infant and older children. Male to female ratio was 1.6:1. Seizure was the most common presentation 34(91.66%) but it has no statistical significance related to mortality. GCS was <8 during presentation in 22(45.83%) cases. Viral analysis done in CSF of 12 patients (25.0%) where Herpes virus was found in 16.6%. Number of patients improved with sequel 68.75% & improved without any sequel 31.25%. Hyponatremia, shock & need of mechanical ventilation was statistically significant regarding mortality. Hypernatremia didn’t seem to influence the mortality significantly. Conclusion: Hyponatremia being significantly associated with mortality among children with Acute Encephalitis, warrants detailed evaluation to define its association with etiology and appropriate management. Maintaining euvolemia, prompt identification of shock and appropriate use of inotropes is of utmost importance. Patients presenting with low GCS score & those who need mechanical ventilation high supervision should be provided due to their poor outcome. Diverse and changing etiologies pose a diagnostic challenge and to find out etiology should be emphasized.