Patients with acute myeloid leukemia (AML) who fail to achieve complete remission (CR) have a dismal prognosis. Although data suggest that durable remissions can be achieved in approximately 30% of patients with refractory or relapsed AML after allogeneic hematopoietic cell transplantation (HCT), only a small fraction of those patients are offered this therapeutic option. Importantly, patients with primary refractory AML have distinctly better outcomes following allogeneic HCT than those with refractory relapse. Access to suitable donors could be one of the main barriers in these situations. However, with recent developments in the field of allogeneic HCT, such as alternative donor sources, high-resolution HLA-typing, reduced intensity conditioning regimens and improvements in supportive care, this approach has the potential to offer long-term survival for patients with refractory and relapsed AML and should be considered as early after diagnosis as possible. Incorporating novel agents into the conditioning regimen or as post-transplant maintenance therapy could further improve outcomes and render older or medically infirm patients with refractory or relapsed AML eligible for allogeneic HCT. In this review, we summarize existing data on allogeneic HCT in patients with refractory or relapsed AML and explore novel approaches with the potential to improve outcomes in this patient population.