Background: Platelet and Red blood cell indices ratios serve as a simple and convenient stratification tool for illness severity predictors in pediatric intensive care unit (PICU) mortality. The aim of the current study was toevaluate the ability of red cell distribution width (RDW) and platelet indices and ratios to predict mortality. Patients and methods: A prospective, observational study was conducted on 99 critically ill children of both sexes admitted to PICU of Benha University Hospitals and Benha Children Hospital (BENCH). All children incorporated in this study were subjected to careful history taking, clinical examination, complete blood count (CBC) and scoring by the third-generation pediatric index of mortality (PIM-3). Results: Our results showed that RDW, platelet counts and platelet indices ratios independently predicted PICU mortality. RDW measured within 24 hours of PICU admission was independently associated with mortality (p=0.001). Although RDW demonstrated high sensitivity (94.8 %) but low specificity (37.1%) as an independent predictor of mortality, it corresponded fairly to sensitivity and specificity of PIM-3 score in the present study. This is an important observation as a low-cost test of RDW performed nearly at par with more complex index of mortality. Regarding platelet indices, our study found that the platelet ratios [Mean platelet volume (MPV)/ plateletcrit (PCT), MPV/ platelet count, platelet differential width (PDW)/PCT, PDW/Platelet count] were better predictors of mortality than platelet indices by themselves. All the ratios of platelet indices were statistically significant (p-value <0.05). Conclusion: RDW, platelet count, and platelet indices ratios were independent predictors of PICU mortality. The predictive power of these indices was comparable to the PIM-3 score.