Tissue engineering offers new opportunities for meniscus repair and replacement. In this field different approaches are being studied to genererate a meniscus subsitute by a combination of a matrix scaffold, cells and specific stimuli. MENISCUS REPLACEMENT BY ACELLUAR MATRICES: For meniscus replacement the matrix material has to meet high biomechanical demands. Besides implant geometry, the material properties and a secure intraarticular attachment are important preconditions for implant function. A collagen scaffold has already been applied clinically for partial meniscus replacement. Scaffolds made of synthetic, bioabsorbable polymers and small intestine submucosa have been employed in animal studies. Following implantation, matrices are invaded by cells and undergo a process of remodeling. Formation of fibrocartilage repair tissue has been observerd. The biomechanical quality of implants and their effect on cartilage preservation have to be studied further. CELLULAR SEEDING OF MATRICES FOR MENSICUS REPLACEMENT: Advanced biological and biomechanical implant quality might be achieved by seeding matrices with cells in vitro. However, the ideal type of cell for this purpose has not yet been identified. Autologous mensicus cells, articular chondrocytes and mesenchymal stem cells represent possible cellular sources. Additional stimuli, such as cytokines and mechanical forces, and techniques of genetic engineering might further contribute to enhance the quality of engineered tissue.