The present study aims to evaluate the efficacy of matrix-induced adipose-derived mesenchymal stem cells (Ad-MSCs) for cartilage repair of focal chondral knee lesions. Twenty patients were initially treated for symptomatic full-thickness chondral defects and then prospectively followed for two years. All patients underwent a single- stage procedure consisting in filling each defect with autologous culture-expanded mesenchymal stem cells embedded in a trimmed-to-fit commercially available biodegradable matrix. Knee-related function was evaluated based on subjective scores given by two self-reported questionnaires (KOOS and IKDC). Data analysis shows significant improvements (p<0.001) in all values. The mean preoperative scores in the subscales of KOOS, as well as in the IKDC subjective score were constantly increased during the follow-up period with statistically significant differences at 6, 12 and 24 months follow-up. The findings of this study indicate that matrix- induced adipose-derived mesenchymal stem cells implantation is an effective and safe single-staged cell-based procedure to manage full-thickness focal chondral lesions of the knee.