A method for treating mammalian articular cartilage disorders, more particularly osteoarthritis, and trauma-related cartilage injuries using insulin-like growth factor I (IGF-I) is provided. The method comprises increasing the amount of IGF-I at the diseased or injured articular site to a therapeutically effective level that is capable of maintenance and/or regeneration of cartilage, which is beneficial to the long-term treatment of osteoarthritis and trauma-related injuries to cartilage tissues. In one embodiment of the invention, single doses of at least 0.01 mg of pharmaceutically effective IGF-I are administered intermittently such that the duration of time off of therapy is greater than the time on therapy, more preferably with a frequency of administration of about once per week or less.