Abstract The production of lactate by slices of bovine articular cartilage incubated in vitro remains unchanged despite deprivation of oxygen or the addition of 10 −3 or 10 −4M of sodium cyanide. Lactate generation is markedly lowered in the presence of 10 −4M of sodium monoiodoacetate (MIA) and increased by 10 −4M dinitrophenol (DNP). The LDH isoenzyme pattern of articular cartilage from rabbit, cow, and man contains mostly LDH 4 and LDH 5 isoenzymes, which have been suggested as facilitators of anaerobic glycolysis. These findings suggest that anaerobic metabolism (glycolysis) is the major pathway for energy generation in articular cartilage. They further suggest that the function of mitochondria in articular cartilage might be substantially different from mitochondrial function in most other tissues.