Joint and soft tissue injections can be divided into two primary categories: diagnostic and therapeutic. Diagnostic injections facilitate a diagnosis by using a local anesthetic to identify the site of pain or through fluid aspiration for analysis. Therapeutic injections are categorized by the type of injectate and include corticosteroids, hyaluronic acid, dextrose prolotherapy, and platelet-rich plasma. Diagnostic and therapeutic injections are most accurate under direct visualization. Corticosteroid injections help treat adhesive capsulitis and tenosynovitis but are not recommended for intratendinous injections. Hyaluronic acid has limited benefits for knee osteoarthritis. Dextrose prolotherapy injections treat tendinopathy and degenerative joint pain. Platelet-rich plasma injections effectively treat common extensor tendinopathy and knee arthritis; however, the evidence does not support its use for other soft tissue injuries. Preparation for injections includes patient education, consent, proper patient positioning, and obtaining the necessary supplies. Local infection, fractures, and allergy to injection substrates are contraindications to joint and soft tissue injections. Potential complications include pain, swelling, and redness. Corticosteroid injections into soft tissue may cause atrophy and depigmentation, and repeated injections can cause cartilage and tendon degeneration. Optimizing conservative, noninjection treatments, such as oral and topical analgesics, activity modification, or rehabilitation, is also important.