Articular cartilage injuries in the knee are common; fortunately, full-thickness articular cartilage defects constitute only a small portion of this group. These lesions may be incidentally encountered during ligament or meniscal surgery, having been silent or asymptomatic for an unknown period of time. However, when they are large and symptomatic, the surgeon may choose from a wide array of techniques available for treatment. The relatively small number of natural history studies regarding full-thickness articular surface lesions complicates the decision-making process. Accurate evaluation and classification of the anatomic defect aids in the development of a clinical algorithm for treatment. Surgical techniques are either reparative or restorative in nature. Reparative techniques fall short of complete reestablishment of the articular cartilage; however, the resultant repairs may remain quite functional for varying periods of time. Restorative techniques attempt to reestablish the native articular surface. To date, no peer-reviewed, prospective, randomized, controlled studies of operative versus nonoperative treatment for full-thickness articular cartilage lesions have been published. Even though the long-term results of surgical treatment for full-thickness articular surface lesions remain unknown, the early results are encouraging.