Autologous chondrocyte implantation is an established method for the treatment of chondral defects. However there is insufficient evidence to say whether cell -based therapy is superior to other treatment strategies in articular cartilage lesions. In this work we have determined cell viability of animal and human condrocytes in several passages to identify the specific cell passage that is more appropiate to be used in tissue engineering. We compare the results using tripan blue, X-Ray electron probe microanalysis and microarrays. When tripan blue is used a high viability--more than 80 %--was observed in all passeges. When it was used X-Ray microanalysis the K/ Na index only showed high viability in some subcultures. Whereas only cell death with ruptured cell membrane are stained with tripan blue, X-ray microanalysis determination detecs cell death before the rupture of the membrane. The gene expression for caspase and chondral differentiation confirm the heterogeneity in cell viability for different cell passages and therefore the possible influence of cell viability in the effectiveness of autologous chondrocyte implantation.