Purpose The aim of this study was to perform a systematic review of studies concerning current treatment of chondral defects of the knee. Methods The relevance for evidence based data and for successful surgical treatment of cartilage defects was evaluated. From 56,098 evaluated studies, 133 studies could be further pursued. These supplied data concerning microfracturing, the osteochondral autograft transplantation system (OATS), the autologous chondrocyte implantation (ACI) and the matrix induced chondrocyte implantation (MACI). The modified Coleman Methodical Score (CMS) and the Level of Evidence (LOE) were applied to evaluate the quality. Results In these studies, a total of 6,920 patients were reviewed with a median of 32 patients per study and a mean follow-up of 24 months. The mean CMS was 58 of 100 points. No study reached 100 points in the CMS. Three studies reached a level above 90. Ten studies were Level I, five studies reached Level II. Seven studies reached Level III, 111 studies Level IV. MRI scans to verify the clinical data were used by only 72 studies. The means in the modified CMS were for the different procedures as follows: ACI 58 points, MACI 57 points, microfracturing 68 points and OATS 50 points. 24 studies applied the Lysholm Score (LS) for clinical evaluation of cartilage surgery. All operative procedures yielded comparable improvements of the LS (n.s.) meaning that no operative procedure proved superior. Conclusion As the majority of studies evaluated by this review is insufficient for EBM purposes more coherent studies with LOE of I or II are needed. Co-relating the systems of CMS and LOE and validating the applied scores seems desirable.