This is a clinical practice guideline for stem cell transplantation (SCT) in the treatment of acute lymphoblastic leukemia. The guideline establishes indications for allogeneic stem cell transplantation (allo-SCT) in the management of acute lymphoblastic leukemia (ALL) in adults. It identifies the role of reduced-intensity conditioning (RIC) regimens for SCT in the management of ALL adult patients, and the role of tyrosine-kinase inhibitors (TKIs) for patients undergoing allo-SCT for Philadelphia chromosome-positive ALL (Ph+ ALL). The guideline also discusses the role of alternative donor transplantation (haploidentical, cord blood) in the management of adult patients with ALL who lack a suitable donor. Outcomes of interest are relapse, disease-free survival, relapse-free survival, progression-free survival, and overall survival.