Sixty-five articular cartilage knee lesions were diagnosed by arthroscopy over a 5-year period, and classified according to the age, the size, the depth, and the location of the lesion. The purpose of this study was to evaluate surgical outcome of a standardized treatment regimen consisting of complete vertical excision of diseased or injured articular cartilage followed by drilling of the subchondral bone plate. A standardized postoperative rehabilitation protocol was used, which included non-weight bearing for eight weeks. Overall clinical results at two years revealed 69% good, 3% fair, and 28% poor knees. Seventy-one percent of patients underwent follow-up arthroscopy at 1 year and 57% consented to biopsy. Retrospective analysis revealed that the group with the best prognosis consisted of small-to-medium acute partial thickness lesions on the weight bearing portion of the femoral condyles. Ninety-five percent of this group had good results.