BACKGROUND: The Lower Quarter Y-Balance Test (YBT-LQ) has been shown to be reliable for assessing dynamic balance in children and adolescents. However, limited research is available about the effects of leg dominance on YBT-LQ performance in adolescents. In addition, there is no consensus on the use of maximum reach or mean reach distance being a better measure of YBT-LQ performance. HYPOTHESIS/PURPOSE: The purposes of this study were to determine if there is a difference in the YBT-LQ performance between the dominant and non-dominant limbs in non-athlete adolescents, and to compare the reliability of the maximum reach scores to that of the mean reach scores in this population. STUDY DESIGN: Prospective cohort study. METHODS: Twenty-six healthy non-athlete adolescents (13.6 ± 1.0 years, 22 girls, 4 boys) performed the YBT-LQ on two separate days while the same investigator scored their performance. Paired -tests were used to compare reach distances on dominant and non-dominate stance limbs. Intraclass correlation coefficients (ICC) were calculated for the maximum and mean reach distances for three directions (anterior, posterolateral, posteromedial) and the composite scores on each limb. RESULTS: There was no significant difference in YBT-LQ performance between dominant and non-dominant stance limbs ( > 0.05). Overall, the between-day intra-rater reliability for maximum reach and mean reach scores was moderate-to-good for both limbs (ICC = 0.59 - 0.83), but was poor for the composite score on the dominant limb (ICC = 0.42) and maximum anterior reach on non-dominant limb (ICC = 0.48). CONCLUSION: Limb dominance does not seem to be a factor for YBT-LQ performance in this population. The YBT-LQ appears to be a reliable tool for dynamic balance assessment in non-athlete adolescents using the individual score of each direction. The use of mean reach measures seems to slightly improve reliability, specifically the anterior reach direction, in this population. LEVEL OF EVIDENCE: Level 2b.