The biceps curl test is easy to apply, does not require expensive equipment, and its short execution time makes it feasible in school settings with limited resources. To verify the reliability of the biceps curl test in children and adolescents and to provide reference values according to chronological age and sex. A total of 1103 schoolchildren aged 6 to 17 years (500 boys and 603 girls) were evaluated. Weight and height were evaluated and Body Mass Index (BMI) and Tri Ponderal Index (TPI) were calculated. The right and left hand biceps curl was evaluated in 30 s. Children aged 6 to 11 years used a 1 kg dumbbell and those aged 12 to 17 years used a 2 kg dumbbell. Percentiles were calculated using the LMS method. The values of the relative Technical Error of Measurement (TEM%) of the biceps curl test of both hands ranged from 0.48 to 2.89%. The intraclass correlation coefficient (ICC) evidenced high values of 0.93 to 0.99. The Bland-Altman plot showed wide limits of agreement (-1.28 to 1.29 rep). These findings demonstrate that the test is reliable and consistent for use in pediatric populations and is suitable for different stages of physical development in school children. The values showed stability and wide limits of agreement. In addition, the proposed percentiles are useful to evaluate and monitor the strength endurance performance of both arms.