© 2020 Elsevier LtdPurpose: Stem cells are collected from donors and infused to the recipient in allogenic peripheral stem cell transplantations. The use of frozen stem cells can promote donor compatibility, and overcoming possible problems due to insufficient stem cell mobilization will also be easier. Nevertheless, studies about the use of frozen peripheral stem cells in allogenic transplantation are extremely rare. In this study, we aimed to compare the clinical outcomes of allogenic stem cell transplants from frozen or fresh stem cell products. Materials and methods: This retrospective analysis was conducted between April 2004 and September 2018 in the bone marrow transplantation unit of Ankara Numune Training and Research Hospital. Clinical data of patients who received allogenic peripheral stem cell transplantations from fully matched sibling donors were compared for 42 fresh and 30 frozen stem cell transplants. Results: While the platelet engraftment period, febrile neutropenia period, hospitalization period, and 100-day mortality rates did not show any differences, the neutrophil engraftment period was longer in the frozen group (mean: 14 days vs. 16 days, p = 0.006). Acute and chronic graftversus-host disease (GVHD) rates were similar in both groups; however, the rate of grade 3 or4 chronic liver GVHD was slightly higher in transplants performed with fresh stem cells compared to the frozen group (p = 0.046). Overall survival was similar between the groups (p = 0.700). Conclusion: The use of frozen peripheral stem cells in allogenic stem cell transplantation may be a reasonable option that can be applied without causing a significant change in clinical results.