Injection of corticosteroid preparations for the local treatment of musculoskeletal disorders affecting the knee, such as osteoarthritis and rheumatoid arthritis, has been used widely since the 1950s. This local therapy minimizes systemic toxicity and can result in rapid improvement in symptoms, most often as an adjunctive therapy for acute or severe symptom flares. The evidence assessing safety and efficacy is reviewed and analyzed. Intra-articular knee injection technique is described and is a procedure that is easy to learn and can be performed quickly in an office or hospital setting.