Context: To treat anterior cruciate ligament (ACL) injury, ACL reconstruction (ACLR) surgery is currently a standard of the care. However, effect of graft type including bone–patellar tendon–bone (BTB), hamstring tendon, or iliotibial band (ITB) on thigh size, knee range of motion (ROM), and muscle strength are understudied. Objective : To compare postoperative thigh circumference, knee ROM, and hip and thigh muscle strength in adolescent males who underwent ACLR, based on the 3 different autograft types: BTB, hamstring (HS), and ITB. Setting: Biomechanical laboratory. Participants: Male ACLR patients who are younger than 22 years of age (total N = 164). Intervention: At 6- to 9-month postoperative visits, thigh circumference, knee ROM, and hip and thigh muscle strength were measured. Main Outcome Measures: Deficits of each variable between the uninvolved and ACLR limb were compared for pediatric and adolescent ACLR males in the BTB, HS, and ITB cohorts. Baseline characteristics, including physical demographics and meniscus tear status, were compared, and differences identified were treated as covariates and incorporated in analysis of covariance. Results: Data were from 164 adolescent male ACLR patients [mean age 15.7 (1.2) years]. There were no statistical differences in thigh circumference, knee ROM, hip abductor, and hip-extensor strength among the 3 autografts. However, patients with BTB demonstrated 12.2% deficits in quadriceps strength compared with 0.5% surplus in HS patients (P = .002) and 1.2% deficits in ITB patients (P = .03). Patients with HS showed 31.7% deficits in hamstring strength compared with 5.4% deficits in BTB (P = .001) and 7.7% deficits in ITB (P = .001) groups at 6- to 9-month postoperative visits. Conclusion: Adolescent male ACLR patients with BTB and HS autografts demonstrated significant deficits in quadriceps and hamstring strength, respectively, at 6 to 9 months postoperatively. Minimal lower-extremity strength deficits were demonstrated in pediatric male ACLR patients undergoing ITB harvest.