Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 60 3 2022 03 14 156 164 Elham Roshandel Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.. Mohsen Hamidpour Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. AND Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Haniyeh Ghaffari Nazari Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Shayan Zamani Students’ Scientific Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hassani Department of General Surgery, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Anahita Saeedi Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Science, Tehran, Iran. Abbas Hajifathali Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Science, Tehran, Iran. 2020 10 29 2021 12 11 Organ failure, including; liver toxicity, renal failure, and neurotoxicity, are frequent complications following HSCT which can affect the transplant outcome, morbidity, and mortality of allo-HSCT recipients: A retrospective study of 206 allo-HSCT patients was conducted to determine the frequency of organ failure and overall survival in patients receiving allo-HSCT. Liver toxicity, renal failure, and neurotoxicity were diagnosed according to clinical and laboratory records pre and post-allo-HSCT. A total of 33 patients (16%) developed organ failure within 200 days after allo-HSCT. Liver toxicity was diagnosed in 12% of patients, and the median time of its occurrence was 22 days (range: 0-207 days) post-allo-HSCT. Two percent (6 of 206) of allo-HSCT recipients presented renal failure. Renal failure was developed within the median time of 33 days (range: 5-88 days). Neurological involvement occurred in 0.9% of patients. Among 206 patients, the frequency of complications such as veno-occlusive disease (VOD) and graft-versus-host disease (GVHD) was 1.4% and 16.01%, respectively. One-year overall survival of patients who had organ failure was 24%, and the mean survival determined 329±99.58 days. Three-month overall survival of patients who developed liver injury and renal failure were 78% and 33%, respectively. Organ failure remains a common complication in patients who received allo-HSCT. Patients with GVHD and two or multi-organ involvement seem to have lower overall survival. https://acta.tums.ac.ir/index.php/acta/article/view/8907