Abstract: Ayán Pérez, C, Cancela, JM, Senra, I, and Quireza, E. Validity and reliability of 2 upper-body strength tests for preschool children. J Strength Cond Res 28(11): 3229–3238, 2014—The “bent knee push-up” and the “timed dipping” are 2 upper-body strength assessment tests whose simplicity and ease of use make them suitable to be applied to preschool children. Nevertheless, their psychometric properties have not been properly studied for this age group. This study aimed to fill this gap. To accomplish this, both tests were administered 3 times (familiarization, test, and retest) to a group of 120 children (mean age, 48.60 ± 9.94 months; body mass index, 17.05 ± 2.04 kg·m−2; 50% girls), with a week interval between each assessment. The obtained results in each test were compared with those obtained in the “handheld dynamometry” (the criterion measure) with the aim of identifying their construct validity. The reliability of the tests was analyzed by comparing the obtained results during the second (test) and the third (retest) time that each 1 was carried out. Intraclass correlation coefficients (ICCs) were used to examine reliability, and Pearson’s correlation coefficients were used to examine validity. The bent knee push-up showed a moderate reliability for 3-year-old children (ICC, 0.690; 95% confidence interval [95% CI], 0.379–0.845) and high for those aged 4 years (ICC, 0.848; 95% CI, 0.715–0.919) and 5 (ICC, 0.702; 95% CI, 0.441–0.841). Similar results were obtained for the timed dipping, in children aged 3 years (ICC, 0.522; 95% CI, 0.422–0.761), 4 years (ICC, 0.766; 95% CI, 0.560–0.875), and 5 years (ICC, 0.828; 95% CI, 0.677–0.908). Both tests showed a good construct validity, with the exception of the timed dipping in 3-year-old children (r = 0.200; p = 0.256). The results in this study suggest that the bent knee push-up and the timed dipping show psychometric properties that make them suitable to be used in research carried out with preschoolers.