Background: Assessing high-sensitivity C-reactive protein (hs-CRP) in relation to allergic endpoints can shed light on both the mechanisms of allergic disease development and early non-communicable disease prevention. However, only a few epidemiological studies so far have investigated the relationship in children and adolescents, and the results were mixed. Objectives: We sought to examine the interrelation between hs-CRP levels and allergic outcomes using a larger population size and a longitudinal study design. Methods: Complete data were available on 1,955 participants from the 15-years follow-up of the 2 large populationbased German birth cohorts -GINIplus and LISA. Serum hsCRP concentrations were measured using the immunoturbidimetric high-sensitive assay. Six allergic endpoints were used -doctor-diagnosed asthma, doctor-diagnosed eczema, doctor-diagnosed allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization. We used generalized estimation equation models to assess the asso-ciations between hs-CRP levels and allergic endpoints. Results: Our longitudinal analyses did not detect any significant association between hs-CRP levels and any of the studied allergic outcomes (e.g., asthma, eczema, allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization). The results were consistent in a series of sensitivity analyses. Conclusions: Our study suggests that there is no association between hs-CRP levels and any of the allergic endpoints in German adolescents. However, whether allergic diseases are inflammatory conditions and which markers might be most sensitive, remain to be confirmed in future studies.