The aim of the study was to assess regeneration of hyaline cartilage femoral condylar articular surface lesions after cultured autologous chondrocytes implantation. 42 implantations of autologous chondrocytes were performed. In 5 patients, 15-30 months after the first surgery, repeat knee arthroscopy was performed. During the repeat arthroscopy a microbiopsy from articular surface was taken and histopathologic analysis was performed. In all cases lesion healing was observed and the general appearance as well as cartilage resilience did not differ from the surrounding tissues. In 4 patients the lesion was filled with hyaline-like cartilage while in 1 patient the lesion was filled with hyaline and fibro-hyaline cartilage.