Context: There is a logical connection with biomarkers, trauma, and sepsis. This review paper provides new information and clinical practice implications. Biomarkers are very important especially in pediatrics. Procalcitonin and other biomarkers are helpful in identifying neonatal sepsis, defense mechanisms of the immune system. Pediatric trauma and sepsis is very important both in infants and in children. Stress management both in trauma is based upon the notion that stress causes an immune imbalance in susceptible individuals. Evidence Acquisition: Data sources included studies indexed in PubMed, a meta-analysis, predictive values, research strategies, and quality assessments. A recent paper by one of the authors stated marked increase in serum procalcitonin during the course of a septic process often indicates an exacerbation of the illness, and a decreasing level is a sign of improvement. A review of epidemiologic studies on pediatric soccer patients was also addressed. Keywords for searching included biomarkers, immunity, trauma, and sepsis. Results: Of 50 reviewed articles, 34 eligible articles were selected including biomarkers, predictive values for procalcitonin, identifying children at risk for intra-abdominal injuries, blunt trauma, and epidemiology, a meta-analysis. Of neonatal associated sepsis, the NF-kappa B pathway by inflammatory stimuli in human neutrophils, predictive value of gelsolin for the outcomes of preterm neonates, a metaanalysis interleukin-8 for neonatal sepsis diagnosis. Conclusions: Biomarkers are very important especially in pediatrics. Procalcitonin and other biomarkers are helpful in identifying neonatal sepsis, defense mechanisms, and physiological functions of the immune system. Pediatric trauma and sepsis is very important both in infants and in children. Various topics were covered such as biomarkers, trauma, sepsis, inflammation, innate immunity, role of neutrophils and IL-8, reactive oxygen species, neonatal hypoxia, NF-kappa B related to inflammation. These topics are clearly linked and are very important for pediatricians, pulmonologists, and immunologists in academic centers and in practice.