['Existing studies of autologous chondrocyte implantation (ACI) in adolescent patients have primarily reported outcomes that have not been validated for cartilage repair and have failed to include measures of general health or health-related quality of life.', 'This study assesses validated knee-specific functional outcomes and health-related quality of life after ACI in adolescent patients.', 'Case series; Level of evidence, 4.', 'Patients younger than 18 years who underwent ACI between 1999 and 2011 with a minimum 2-year clinical follow-up were identified from a prospectively collected database. A total of 37 patients were included in the analysis. Patient demographic data and pre- and postoperative functional outcomes scores were collected and chondral lesion characteristics were assessed. Primary outcome measures were the International Knee Documentation Committee (IKDC) subjective score and the Knee Injury and Osteoarthritis Outcome Score-Quality of Life (KOOS-QOL) subscore; secondary outcome measures were Short Form-12 (SF-12) and other KOOS subscores. In subgroup analyses, we assessed whether primary outcome results differed based on lesion location, concurrent meniscal allograft transplantation (MAT), and subsequent surgery after ACI.', 'Study patients had a mean 4.6 ± 2.4 years of follow-up, a mean age of 16.7 ± 1.5 years, and a mean lesion size of 4.0 ± 2.2 cm'] Does autologous Chondrocyte Implantation improve Knee-Specific Functional Outcomes and Health-Related Quality of Life in Adolescent Patients?