Complications can arise with any surgical procedure, including bone grafting treatments. This chapter reviews the evidence emphasizing a systematic approach to managing bone grafting patients, including thorough history and exams, careful treatment planning tailored to the individual, meticulous surgical technique, and organized follow-up care. The chapter first discusses complication etiologies in two sections—those related to systemic conditions like diabetes, radiation, chemotherapy, medications, and social habits; and those related to technical aspects of procedures like GBR, socket preservation, sinus lifts, and block bone grafting. It then classifies common complications such as incision dehiscence, graft infection, graft resorption, and fixation failure. Graft procedure-specific complications are also addressed in detail, including those associated with nonvascular bone grafts, free vascular bone grafts, and tissue engineering procedures.