Matched sibling donor (MSD) hematopoietic stem cell transplantation (HSCT) remains the standard first-line therapy for young patients with severe aplastic anemia (SAA). Advances in conditioning regimens, supportive care, and donor matching have significantly improved outcomes, with survival rates exceeding 90% in children and young adults. Key pretransplant factors influencing success include age, disease severity, transfusion history, and infection status. Cyclophosphamide with anti-thymocyte globulin (Cy-ATG) remains the gold-standard conditioning regimen, while fludarabine-based protocols offer alternatives for older or high-risk patients. Bone marrow (BM) is the preferred stem cell source due to lower graft-versus-host disease (GvHD) risk. Chimerism monitoring, immunosuppression, and management of complications post-transplant are crucial for long-term success. Syngeneic HSCT offers unique advantages with minimal toxicity, though rare. With tailored regimens and early intervention, MSD HSCT offers curative potential for SAA, minimizing the risk of relapse, graft failure (GF), and clonal evolution. Long-term follow-up remains essential to optimize patient outcomes.