This study examined whether 6 weeks of twice-weekly in-season hamstring eccentric training would enhance selected performance-related abilities in prepubescent male weightlifters. Twenty elite weightlifters (11.1 ± 0.8 years) were randomly split into an eccentric training intervention group (INT n = 10) or a control group (CON) that maintained their standard in-season regimen (n = 10). Pre and post intervention Speed, Dynamic Balance, Muscle Strength, Power and Lower Limb Asymmetry were assessed. ANCOVA controlling for maturation was used to determine any differences in the performance variables. There were no significant changes in muscle strength, dynamic balance or lower limb asymmetry (all P< 0.05) because of the intervention. Both 10m (P= 0.001) and 30m (P= 0.007) sprint speed and agility (P=.049) improved to a greater extent in INT compared to the CON group. Similar results were evident for the standing long jump (P= 0.015) and 3 hop test (P = 0.004) were performance improved to a greater magnitude in INT compared to CON groups. This study suggests that eccentric training, undertaken twice weekly for 6-weeks result in positive changes in sprint speed, change of direction speed and power performance, but not muscle strength, dynamic balance or lower limb asymmetry in prepubertal weightlifters.