The body of literature concerning studies of the applications of CRP measurement in the pediatric population continues to grow. Based on current data serial CRP measurements appear to be most useful for monitoring patient response to therapy after the primary diagnosis of invasive infectious or inflammatory diseases, for monitoring patients after major surgical procedures and those with serious burns. Monitoring CRP over time may be used to assess for recrudescent disease, a secondary process or ineffective therapy. In addition CRP appears to be suited to most applications for which the ESR is used but offers many advantages. At present there are no objective outcome-based clinical trial data to justify using CRP values alone, whether elevated or normal, as a basis for management decisions regarding instituting or withholding antimicrobial therapy, or its early discontinuance for patients suspected of having neonatal sepsis, meningitis, bacteremia or pneumonia, regardless of immune status. In addition, because of significant inconsistencies among studies for which CRP has been applied to differential diagnosis of bacterial vs. viral diseases, including meningitis, acute otitis media and lower respiratory tract infection, we cannot recommend it for this purpose. Data do not support a role for CRP in differential diagnosis of acute appendicitis or for localizing urinary tract infections.