To analyse the frequency, risk factors, and clinical symptoms of acute graft-versus-host disease (aGvHD) in patients with beta-thalassemia major after allogeneic haematopoietic stem cell transplantation (HSCT). Descriptive study. Place and Duration of the Study: Department of Clinical Haematology, Armed Forces Bone Marrow Transplant Centre, Rawalpindi, Pakistan, from January 2017 to December 2021. Data were obtained from patients diagnosed with bone and tissue malignancies (BTM) who had undergone haematopoietic stem cell transplantation (HSCT) and experienced aGVHD. Patients who experienced initial graft failure and individuals who underwent subsequent bone marrow transplantation were excluded. Total of 117 patients diagnosed with BTM underwent fully matched HSCT, including 76 (65%) males, and 41 (35%) females. The median age of the patients undergoing transplantation was 7.34±7.32 years and the donors' median age was 7.6±9.85 years. Among the donors, 53 (45.3%) were males and 64 (54.7%) were females. Gender disparity was observed in 46 (39.3%) instances as a female donor matched with a male recipient. A total of 106 individuals underwent bone marrow harvest (BMH); with 5 (4.3%) patients receiving peripheral blood stem cells (PBSC) and 6 (5.2%) patients receiving both BMH and PBSC. Acute GvHD was observed in 50 (42.7%) patients, including 30 (60%) males and 20 (40%) females. Grade I GvHD occurred in 32 (27.3%) individuals, Grade II GvHD in 16 (13.7%) patients, and Grade III GvHD in one (0.8%) patient. It had no statistically significant association with recipient/donor age, gender disparity, the source of the graft source, the dose of stem cells, or the presence of thymoglobulin (TG). Acute GvHD was observed in high frequency in Beta-thalassemia patients receiving morrow harvesting proportional to their gender distribution. Associated factors were GvHD prophylaxis measure, mucositis and, CMV reactivation. Beta thalassemia major patients, Acute graft versus host disease, Allogeneic haematopoietic stem cell.