This study aims to develop BMI percentiles for German children and adolescents, addressing the lack of national reference data in Germany. The authors compiled BMI data from 17 regional studies involving 17,147 boys and 17,275 girls aged 0-18 years. The percentiles were calculated using the LMS method, which characterizes the distribution of BMI at different ages and genders. The resulting percentiles are recommended as a reference for assessing overweight and obesity in German children and adolescents. The "Arbeitsgruppe Adipositas im Kindes- und Jugendalter" (AGA) guidelines suggest using the 90th and 97th percentiles as cut-off points for defining overweight and obesity. The study highlights the importance of age- and sex-specific BMI changes in children and adolescents, which are not accounted for in adult definitions. The presented percentiles are intended to improve the diagnosis and management of adiposity in this age group.This study aims to develop BMI percentiles for German children and adolescents, addressing the lack of national reference data in Germany. The authors compiled BMI data from 17 regional studies involving 17,147 boys and 17,275 girls aged 0-18 years. The percentiles were calculated using the LMS method, which characterizes the distribution of BMI at different ages and genders. The resulting percentiles are recommended as a reference for assessing overweight and obesity in German children and adolescents. The "Arbeitsgruppe Adipositas im Kindes- und Jugendalter" (AGA) guidelines suggest using the 90th and 97th percentiles as cut-off points for defining overweight and obesity. The study highlights the importance of age- and sex-specific BMI changes in children and adolescents, which are not accounted for in adult definitions. The presented percentiles are intended to improve the diagnosis and management of adiposity in this age group.