The sacroiliac joint is a common cause of low back pain, and techniques to reduce pain and improve function are of utmost interest to the pain medicine practitioner. As regenerative medicine continues to expand, a thorough understanding of the types of therapies that make up the regenerative medicine toolkit is imperative. This chapter reviews prolotherapy and injections of mesenchymal stem cells, platelet-rich plasma, autologous whole blood, and hyaluronic acid for the treatment of sacroiliac joint–mediated pain. Information on background, mechanisms of action, pharmacology, safety and efficacy, possible side effects, and preparation and administration is provided for each of these regenerative injectants, along with a brief review of clinical trials and published data.