We report the 9-year clinical, radiographic and histological outcome of autologous chondrocyte implantation (ACI) used to treat massive cartilage lesions of the medial femoral condyle and patella in an adolescent patient after osteomyelitis and subsequent septic arthritis of the knee. This is the first reported case of ACI performed in the knee for significant chondral lesions secondary to infective changes. Long-term clinical success was achieved using this method, which was outside the usual indications for ACI.