Sepsis claims thousands of children’s lives every year in the world, despite progress in medical science and diagnostics, and technological approaches to recognize the disease as early as possible. This problem remains relevant both for neonates and for infants, children, and adolescents. Features of the immune response against bacterial infections, including systemic inflammation and multiple organ dysfunction, are the main topics of the manuscript. Modern approaches to laboratory diagnostics of hemostasis disorders and intensive care of septic shock, prognostic assessment for multiorgan failure, and progress in personalized medicine make the problem of sepsis very relevant. Surgical sepsis and the perioperative management of pediatric patients with sepsis are presented in detail in the manuscript. Children with burns and leukemia have specific peculiarities, and treatment of sepsis in these categories of patients involves different therapeutic strategies, similar to those in pediatric patients with infectious diseases. Multiple organ failure and clinical, laboratory, and prognostic assessment with different scales are the key topics of this book.