OBJECTIVE: Dengue Hemorrhagic Fever (DHF) contributes an important role amongst tropical infection illness problem in Indonesia. In the last six months, there were an outbreak incidence in the district of Waingapu, East Sumba causing high morbidity and mortality due to shock manifestations. The Pleural Effusion Index (PEI) is expected to help predict the course of DHF mainly as the shock predictors. PEI in DHF can be identified by in the right lateral decubitus chest X photo. This study aimed to determine correlation between PEI values and incidence of shock manifestations in pediatric DHF.                                                                                                                                          METHOD: This research was conducted as an analytic study with cross-sectional design and retrospective of 67 samples. Data were taken from Umbu Rara Meha General Hospital, Waingapu medical records of pediatric patients with DHF from October 2018 to March 2019. The research population are hospitalized DHF patients and admitted to radiology examination. The diagnose was confirmed by clinical, laboratory findings, and radiological manifestations. Data were analyzed by non parametric test Mann Whitney analysis. RESULT: There were 67 DHF patients who were referred to do the radiology x-ray examination consisting of 45 shock (67%) and 23 non shock (34%). 13 subjects (19,4%) had PEI >50% and 54 subjects (80,5%) had PEI <50%. The results showing there was a significant correlation of PEI Index and Shock Manifestations in pediatric Dengue Hemorrhagic Fever (p = 0,000) resulted mean rank in no shock patients (13.11) and shock patients (44.21). We continue to analyze PEI cut off point using ROC, resulting PEI value >50 % will more likely contribute shock manifestation in DHF was statistically significant.                                                                                                     CONCLUSION: Based on this analysis, the greater of PEI value the more it can predict occurrence of shock probability in pediatric DHF patients. PEI >50% has higher risk of shock in DHF than PEI <50%.