Lower-limb strength asymmetry is common among female handball players and may negatively affect athletic performance while increasing injury risk. This randomized controlled trial was designed to investigate the effects of a six-week unilateral compound training program on lower-limb strength asymmetry, isokinetic muscle strength, hamstring-to-quadriceps ratio, body composition, and physical performance in competitive female handball players. Participants were randomly assigned to either an experimental group receiving unilateral compound training in addition to regular handball training or a control group continuing regular handball training only. It was hypothesized that unilateral compound training would reduce strength asymmetry and improve neuromuscular performance compared with regular training alone.