Articular cartilage is a highly specialized tissue composed of chondrocytes which regulate the metabolism of extracellular matrix molecules responsible for maintaining cartilage function. Chondrocytes and synoviocytes are metabolically highly active cells and respond to various factors such as hormones, cytokines, growth factors, and mechanical stresses. Under normal physiological conditions, degradation and synthesis of extracellular matrix molecules are maintained in a state of balance. Any disruption of this balance results in degenerative cartilage diseases such as osteoarthritis and rheumatoid arthritis. Currently, diagnoses of both diseases are based on the assessment of a combination of clinical symptoms and radiological findings. However, degenerative changes in the articular cartilage occurs long before radiological changes are observed. Therefore, new laboratory tools are required to detect cartilage degradation in the early phase of the disease, to show the progression of cartilage destruction, and to assess response to treatment. In recent years, there has been an increase in the use of some biochemical markers derived from bone and cartilage for the diagnosis and follow-up of cartilage diseases. In this paper, the utility of these markers for early diagnosis and follow-up of cartilage injury is discussed in the light of the current literature.