Introduction: Gamma glutamyl transferase (GGT) and uric acid (UA) are reported to be predictive markers in various disorders. It has been reported that these biomarkers can be used to indicate increased risk of mortality in critically ill patients. Herein, we aimed to evaluate the effects of the initial serum GGT and UA levels on the outcomes of patients in the pediatric intensive care unit (PICU) and to investigate if these biomarkers can be used to predict pediatric mortality. Materials and Methods: The relationship between the initial GGT and UA levels and invasive mechanical ventilation (IMV) and noninvasive mechanical ventilation (NIV) support, inotropic drug need, acute renal kidney injury (AKI), continuous renal replacement therapy (CRRT), presence of sepsis, mortality, and hospitalization period were investigated retrospectively. Results: In all, 236 patients (117 males and 119 females) were included in the study. The age distribution of the patients was 1–12 years. There was a statistically significant relationship between GGT levels in the first biochemical analysis performed during admission and inotropic drug use, AKI, duration of hospitalization in intensive care unit, and sepsis. There was a statistically significant relationship between initial UA levels and inotropic drug use, AKI, CCRT, and sepsis. Conclusion: We suggest that initial GGT and UA levels during admission could be used to predict the outcomes of patients in PICU.