Injection techniques are helpful for diagnosis and therapy in a wide variety of musculoskeletal conditions. Diagnostic indications include the aspiration of fluid for analysis and the assessment of pain relief and increased range of motion as a diagnostic tool. Therapeutic indications include the delivery of local anesthetics for pain relief and the delivery of corticosteroids for suppression of inflammation. Side effects are few, but may include tendon rupture, infection, steroid flare, hypopigmentation, and soft tissue atrophy. Injection technique requires knowledge of anatomy of the targeted area and a thorough understanding of the agents used. In this overview, the indications, contraindications, potential side effects, timing, proper technique, necessary materials, pharmaceuticals used and their actions, and post-procedure care of patients are presented.